The performance of organic Rankine cycle (ORC) is mainly influenced by the operating conditions and working fluids. A small-scale ORC experimental apparatus with a scroll expander is established. This work aims to investigate the thermodynamic performance of ORC system under different rotational speeds, turbine inlet pressure and cooling water flow rates. Meanwhile, the performance of pure and mixture fluids, including R245fa, R141b, 0.25R245fa/0.75R141b, 0.5R245fa/0.5R141b and 0.75R245fa/0.25R141b, is experimentally compared to determine a suitable working fluid. The experimental results show that the shaft power, thermal efficiency and exergy efficiency gradually increase with the growth of turbine inlet pressure and cooling water flow rate. However, the ORC system will obtain lower thermal efficiency and exergy efficiency at higher rotational speeds. Mixed fluid can produce more shaft power than pure fluid, and the mass fraction of R245fa/R141b to achieve the best thermodynamic performance is 0.25/0.75. When the cooling water flow rate is 0.6m 3 /h, the maximum shaft power, thermal efficiency and exergy efficiency of 0.25R245fa/0.75R141b are 813 W, 5.63% and 24.18% respectively, which are 14.5%, 19.3% and 18.4% higher than R245fa. Under different operating conditions, the ranges of isentropic efficiency and mechanic efficiency of scroll expander are 47.5-58.9% and 85.6%-99.6, respectively.
{"title":"Experimental Evaluation and Comparison of Organic Rankine Cycle Using Mixture of R245fa/R141b Under Different Operating Conditions","authors":"Zhi-qi Wang, Xiaoxia Xia, Huihui Pan, Baoqi Xie, Yabin Zhao, Zhipeng Liu","doi":"10.2139/ssrn.3892175","DOIUrl":"https://doi.org/10.2139/ssrn.3892175","url":null,"abstract":"The performance of organic Rankine cycle (ORC) is mainly influenced by the operating conditions and working fluids. A small-scale ORC experimental apparatus with a scroll expander is established. This work aims to investigate the thermodynamic performance of ORC system under different rotational speeds, turbine inlet pressure and cooling water flow rates. Meanwhile, the performance of pure and mixture fluids, including R245fa, R141b, 0.25R245fa/0.75R141b, 0.5R245fa/0.5R141b and 0.75R245fa/0.25R141b, is experimentally compared to determine a suitable working fluid. The experimental results show that the shaft power, thermal efficiency and exergy efficiency gradually increase with the growth of turbine inlet pressure and cooling water flow rate. However, the ORC system will obtain lower thermal efficiency and exergy efficiency at higher rotational speeds. Mixed fluid can produce more shaft power than pure fluid, and the mass fraction of R245fa/R141b to achieve the best thermodynamic performance is 0.25/0.75. When the cooling water flow rate is 0.6m 3 /h, the maximum shaft power, thermal efficiency and exergy efficiency of 0.25R245fa/0.75R141b are 813 W, 5.63% and 24.18% respectively, which are 14.5%, 19.3% and 18.4% higher than R245fa. Under different operating conditions, the ranges of isentropic efficiency and mechanic efficiency of scroll expander are 47.5-58.9% and 85.6%-99.6, respectively.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74534889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oil shales belong to lamellar rocks of sedimentary origin. Thermal processing of oil shale yields resins and gases that can be used as energy resources. In theoretical investigation of such processing, one of the primary issues is finding the temperature of external heating. The shale structure exhibits appreciable anisotropy of thermal conductivity, which is not taken account in many theoretical studies. Present work is devoted to theoretical investigation of the effect of anisotropy on the nature of oil shale specimen heating under different location of the heat source forming by high-frequency electromagnetic field.
{"title":"The Effect of Shale Formation Anisotropy on Temperature Distribution Under Local Heating","authors":"A. Knyazeva, A. Maslov","doi":"10.2139/ssrn.3944570","DOIUrl":"https://doi.org/10.2139/ssrn.3944570","url":null,"abstract":"Oil shales belong to lamellar rocks of sedimentary origin. Thermal processing of oil shale yields resins and gases that can be used as energy resources. In theoretical investigation of such processing, one of the primary issues is finding the temperature of external heating. The shale structure exhibits appreciable anisotropy of thermal conductivity, which is not taken account in many theoretical studies. Present work is devoted to theoretical investigation of the effect of anisotropy on the nature of oil shale specimen heating under different location of the heat source forming by high-frequency electromagnetic field.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73811713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-25DOI: 10.15587/1729-4061.2020.219602
N. Sytnik, Ekaterina Kunitsia, V. Mazaeva, A. Chernukha, Pavlo Kovalov, N. Grigorenko, S. Gornostal, O. Yermakova, M. Pavlunko, M. Kravtsov
Production of waxes from spent perlite, which is a waste of sunflower oil winterization, is studied. Winterization is characterized by significant losses of oil with filter powders, and waste utilization is an environmental and economic problem. At the same time, winterization waste contains valuable components – wax and oil, which can be used in different ways. The content of waxes in spent perlite using hexane (18 %), as well as the quality indicators of the obtained wax: melting point 70 °C, saponification number 115 mg KOH/g, acid number 2.6 mg KOH/g, mass fraction of moisture 0,82 % are determined. Spent perlite was treated with a solution of sodium chloride during boiling, settling of the obtained mass, washing and drying of wax. The dependence of the yield and melting point of the extracted waxes on the processing parameters: the concentration of sodium chloride solution, temperature and duration of settling is found. Rational conditions for spent perlite processing are determined: the concentration of sodium chloride solution – 7.5 %, settling temperature – 20 °C, settling duration ‑ 10 hours. The experimentally determined wax yield at this point is 14.3 %. Quality indicators of the wax sample obtained under rational conditions are studied: melting point 68 °С, saponification number 110 mg KOH/g, acid number 2.8 mg KOH/g, mass fraction of moisture 0.85 %. These values correlate with the data for wax extracted using hexane, as well as with reference data on the quality of beeswax and sunflower wax. The data obtained allow recycling spent perlite without organic solvents, which makes the process more environmentally friendly and cost-effective, as well as solves environmental problems associated with the utilization of winterization waste
{"title":"Rational Parameters of Waxes Obtaining From Oil Winterization Waste","authors":"N. Sytnik, Ekaterina Kunitsia, V. Mazaeva, A. Chernukha, Pavlo Kovalov, N. Grigorenko, S. Gornostal, O. Yermakova, M. Pavlunko, M. Kravtsov","doi":"10.15587/1729-4061.2020.219602","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.219602","url":null,"abstract":"Production of waxes from spent perlite, which is a waste of sunflower oil winterization, is studied. Winterization is characterized by significant losses of oil with filter powders, and waste utilization is an environmental and economic problem. At the same time, winterization waste contains valuable components – wax and oil, which can be used in different ways. The content of waxes in spent perlite using hexane (18 %), as well as the quality indicators of the obtained wax: melting point 70 °C, saponification number 115 mg KOH/g, acid number 2.6 mg KOH/g, mass fraction of moisture 0,82 % are determined. Spent perlite was treated with a solution of sodium chloride during boiling, settling of the obtained mass, washing and drying of wax. The dependence of the yield and melting point of the extracted waxes on the processing parameters: the concentration of sodium chloride solution, temperature and duration of settling is found. Rational conditions for spent perlite processing are determined: the concentration of sodium chloride solution – 7.5 %, settling temperature – 20 °C, settling duration ‑ 10 hours. The experimentally determined wax yield at this point is 14.3 %. Quality indicators of the wax sample obtained under rational conditions are studied: melting point 68 °С, saponification number 110 mg KOH/g, acid number 2.8 mg KOH/g, mass fraction of moisture 0.85 %. These values correlate with the data for wax extracted using hexane, as well as with reference data on the quality of beeswax and sunflower wax. The data obtained allow recycling spent perlite without organic solvents, which makes the process more environmentally friendly and cost-effective, as well as solves environmental problems associated with the utilization of winterization waste","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"84 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89025424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fused filament fabrication (FFF) is the most popular additive manufacturing technique to produce three-dimensional complex structures. It is a layer by layer additive manufacturing technique in which parts are created by the addition of one layer over another by using melted thermoplastic polymers. Fused filament fabricated parts have broad applications in automotive, medical, art and adornments fields, etc. The mechanical and thermal properties of FFF printed parts mainly depends on process parameters like infill pattern, layer thickness, infill speed, Nozzle temperature, infill density. The only way to improve the mechanical and surface properties of a part after printing is to make use of the post-processing techniques. Thermal annealing is one of the best post-process treatment for fused filament fabricated parts to improve mechanical properties. The objective of this paper is to provide an overview of the effect of different process parameters on the mechanical properties of fused filament fabricated parts and also investigate the influence of thermal annealing on the mechanical properties of printed parts. Mechanical properties of printed parts are analyzed by conducting different mechanical tests like tensile strength, compressive strength, and impact strength tests, etc. These mechanical tests are conducted on the standard specimens of ASTM or ISO standards. Thermal annealing should be possible by heating the printed part in a temperature range between the glass change temperature (Tg) and the melting point temperature (Tm) of the material used. It is found that the mechanical properties like tensile strength, compressive strength, and impact strength, etc. depend more on the process parameters like infill density, layer thickness, nozzle temperature, etc. It is observed that thermal annealing caused an improvement in flexural strength and tensile strength of fused filament fabricated parts. The tensile test for high tensile PLA showed that the maximum tensile strength furthermore, modulus for the non-heat-treated examples was acquired 65.75 MPa and 4.9 GPa individually, at 250°C. The tensile test results for heat-treated examples exhibited that the maximum tensile strength and modulus were gained 67.4 MPa and 5.65 GPa, separately, at 250°C.
{"title":"Effect of Process Parameters and Thermal Annealing on Mechanical Properties of Fused Filament Fabricated Specimens","authors":"N. C., R. V. Pazhamannil, G. P.","doi":"10.2139/ssrn.3791058","DOIUrl":"https://doi.org/10.2139/ssrn.3791058","url":null,"abstract":"Fused filament fabrication (FFF) is the most popular additive manufacturing technique to produce three-dimensional complex structures. It is a layer by layer additive manufacturing technique in which parts are created by the addition of one layer over another by using melted thermoplastic polymers. Fused filament fabricated parts have broad applications in automotive, medical, art and adornments fields, etc. The mechanical and thermal properties of FFF printed parts mainly depends on process parameters like infill pattern, layer thickness, infill speed, Nozzle temperature, infill density. The only way to improve the mechanical and surface properties of a part after printing is to make use of the post-processing techniques. Thermal annealing is one of the best post-process treatment for fused filament fabricated parts to improve mechanical properties. The objective of this paper is to provide an overview of the effect of different process parameters on the mechanical properties of fused filament fabricated parts and also investigate the influence of thermal annealing on the mechanical properties of printed parts. Mechanical properties of printed parts are analyzed by conducting different mechanical tests like tensile strength, compressive strength, and impact strength tests, etc. These mechanical tests are conducted on the standard specimens of ASTM or ISO standards. Thermal annealing should be possible by heating the printed part in a temperature range between the glass change temperature (Tg) and the melting point temperature (Tm) of the material used. It is found that the mechanical properties like tensile strength, compressive strength, and impact strength, etc. depend more on the process parameters like infill density, layer thickness, nozzle temperature, etc. It is observed that thermal annealing caused an improvement in flexural strength and tensile strength of fused filament fabricated parts. The tensile test for high tensile PLA showed that the maximum tensile strength furthermore, modulus for the non-heat-treated examples was acquired 65.75 MPa and 4.9 GPa individually, at 250°C. The tensile test results for heat-treated examples exhibited that the maximum tensile strength and modulus were gained 67.4 MPa and 5.65 GPa, separately, at 250°C.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76573751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-21DOI: 10.15587/1729-4061.2020.219020
S. Ibraimova, R. Uazhanova, M. Mardar, A. Serikbaeva, N. Tkachenko, D. Zhygunov
In order to determine the influence of juniper fruits (Juniperus communis L) on the formation of bread quality, the optimization of the component composition of a new product with increased nutritional value was carried out. To optimize the recipe composition, the response surface methodology was used. The maximum value of the complex indicator of the quality of new bread is noted when the mass fraction of sodium chloride is 1.45 % and the mass fraction of crushed juniper fruits is 3.17 %. According to the developed recipe, prototypes of the product were developed and the main quality indicators were determined. Based on the analysis of the chemical composition, it was found that bread with the inclusion of 3 % crushed juniper fruits is characterized by an increased content of protein, fiber, vitamins, micro- and macroelements compared to the control sample. The influence of juniper on microbiological parameters and shelf life of the finished product was established. The new type of fortified bread with the addition of 3 % crushed juniper fruits can be stored without changing the quality indicators for up to 72 hours, which exceeds the same indicator of the control bread sample. In the course of the study, the influence of juniper on the antioxidant activity and safety indicators of bread was determined. The inclusion of crushed juniper fruits in the bread made it possible to double the antioxidant activity compared to the control sample, which is 15.5 and 7.5 mg/100 g, respectively. In terms of safety indicators, the developed bread fully meets the requirements of regulatory documents. The results obtained make it possible to recommend for production a new type of fortified bread with increased nutritional value with the inclusion of crushed juniper fruits in its recipe, which will expand the range of health products
为了确定杜松果(Juniperus communis L)对面包品质形成的影响，对一种营养价值更高的新产品的成分组成进行了优化。采用响应面法对配方进行优化。当氯化钠质量分数为1.45%，杜松果碎质量分数为3.17%时，新面包质量综合指标达到最大值。根据开发的配方，开发了产品的原型，并确定了主要质量指标。通过化学成分分析发现，添加3%杜松子碎的面包，其蛋白质、纤维、维生素、微量元素和大量元素的含量均较对照样品有所提高。研究了杜松对成品微生物学参数和保质期的影响。添加3%杜松子碎的新型强化面包可在不改变质量指标的情况下保存长达72小时，超过对照面包样品的相同指标。在研究过程中，测定了杜松对面包抗氧化活性和安全指标的影响。与对照样品(分别为15.5毫克/100克和7.5毫克/100克)相比，在面包中加入粉碎的杜松果使其抗氧化活性增加了一倍。在安全指标方面，研制的面包完全符合规范性文件的要求。所获得的结果使推荐生产一种新型强化面包成为可能，这种面包的配方中含有粉碎的杜松子，具有更高的营养价值，这将扩大保健产品的范围
{"title":"Development of Recipe Composition of Bread With the Inclusion of Juniper Using Mathematical Modeling and Assessment of Its Quality","authors":"S. Ibraimova, R. Uazhanova, M. Mardar, A. Serikbaeva, N. Tkachenko, D. Zhygunov","doi":"10.15587/1729-4061.2020.219020","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.219020","url":null,"abstract":"In order to determine the influence of juniper fruits (Juniperus communis L) on the formation of bread quality, the optimization of the component composition of a new product with increased nutritional value was carried out. To optimize the recipe composition, the response surface methodology was used. The maximum value of the complex indicator of the quality of new bread is noted when the mass fraction of sodium chloride is 1.45 % and the mass fraction of crushed juniper fruits is 3.17 %. According to the developed recipe, prototypes of the product were developed and the main quality indicators were determined. Based on the analysis of the chemical composition, it was found that bread with the inclusion of 3 % crushed juniper fruits is characterized by an increased content of protein, fiber, vitamins, micro- and macroelements compared to the control sample. The influence of juniper on microbiological parameters and shelf life of the finished product was established. The new type of fortified bread with the addition of 3 % crushed juniper fruits can be stored without changing the quality indicators for up to 72 hours, which exceeds the same indicator of the control bread sample. In the course of the study, the influence of juniper on the antioxidant activity and safety indicators of bread was determined. The inclusion of crushed juniper fruits in the bread made it possible to double the antioxidant activity compared to the control sample, which is 15.5 and 7.5 mg/100 g, respectively. In terms of safety indicators, the developed bread fully meets the requirements of regulatory documents. The results obtained make it possible to recommend for production a new type of fortified bread with increased nutritional value with the inclusion of crushed juniper fruits in its recipe, which will expand the range of health products","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79865722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-16DOI: 10.15587/1729-4061.2020.217091
V. Salo, V. Nechiporenko, V. Rakivnenko, S. Horielyshev, Natalia Gleizer, Alexander Kebko
This paper proposes a theoretically substantiated and universal new method to calculate the three-dimensional stressed-strained state of the statically loaded multi-link orthotropic shell of arbitrary thickness, made of heterogeneous material (a composite). The numerical-analytical RVR method used in this work is based on the Reissner principle, Vekua method, the R-function theory, as well as the algorithm of two-way assessment of the accuracy of approximate solutions to variational problems. In contrast to the classical principles by Lagrange and Castigliano, the application of the mixed variational Reissner principle yields an increase in the accuracy of solving boundary-value problems due to the independent variation of the displacement vector and the stress tensor. Vekua method makes it possible, as a result of expanding the desired functions into a Fourier series based on Legendre polynomials, to replace a solution to the three-dimensional problem with a regular sequence of solutions to the two-dimensional problems in the process of refining the models of shells. The R-function theory that takes into consideration, at the analytical level, the geometric information on boundary-value problems for multi-relationship regions is necessary to build the structures of solutions that accurately meet different boundary conditions. When studying spatial boundary-value problems, the constructed algorithm for a two-way integrated assessment of the accuracy of approximate solutions makes it possible to automate the search for such a number of approximations at which the process of solutions’ convergence becomes persistent. For an orthotropic spherical shell made from the material of non-uniform thickness and weakened by the pole holes, the RVR-method capabilities are shown on the numerical examples of solving the relevant boundary-value problems. The results of the reported research have been discussed, as well as the features typical of the new method, which could be effectively applied when designing responsible shell-type elements of structures in the different sectors of modern industry
{"title":"Calculation of the Spherical Elements of Non-Uniform Thickness for Structures With Holes Based on the Variational Rvr Method","authors":"V. Salo, V. Nechiporenko, V. Rakivnenko, S. Horielyshev, Natalia Gleizer, Alexander Kebko","doi":"10.15587/1729-4061.2020.217091","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.217091","url":null,"abstract":"This paper proposes a theoretically substantiated and universal new method to calculate the three-dimensional stressed-strained state of the statically loaded multi-link orthotropic shell of arbitrary thickness, made of heterogeneous material (a composite). The numerical-analytical RVR method used in this work is based on the Reissner principle, Vekua method, the R-function theory, as well as the algorithm of two-way assessment of the accuracy of approximate solutions to variational problems. In contrast to the classical principles by Lagrange and Castigliano, the application of the mixed variational Reissner principle yields an increase in the accuracy of solving boundary-value problems due to the independent variation of the displacement vector and the stress tensor. Vekua method makes it possible, as a result of expanding the desired functions into a Fourier series based on Legendre polynomials, to replace a solution to the three-dimensional problem with a regular sequence of solutions to the two-dimensional problems in the process of refining the models of shells. The R-function theory that takes into consideration, at the analytical level, the geometric information on boundary-value problems for multi-relationship regions is necessary to build the structures of solutions that accurately meet different boundary conditions. When studying spatial boundary-value problems, the constructed algorithm for a two-way integrated assessment of the accuracy of approximate solutions makes it possible to automate the search for such a number of approximations at which the process of solutions’ convergence becomes persistent. For an orthotropic spherical shell made from the material of non-uniform thickness and weakened by the pole holes, the RVR-method capabilities are shown on the numerical examples of solving the relevant boundary-value problems. The results of the reported research have been discussed, as well as the features typical of the new method, which could be effectively applied when designing responsible shell-type elements of structures in the different sectors of modern industry","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82328427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Gajda, Alessio Trivella, R. Mansini, David Pisinger
Abstract We consider a real-world packing problem faced by a logistics company that loads and ships hundreds of trucks every day. For each shipment, the cargo has to be selected from a set of heterogeneous boxes. The goal of the resulting container loading problem (CLP) is to maximize the value of the cargo while satisfying a number of practical constraints to ensure safety and facilitate cargo handling, including customer priorities, load balancing, cargo stability, stacking constraints, positioning constraints, and limiting the number of unnecessary cargo move operations during multi-shipment deliveries. Although some of these constraints have been considered in the literature, this is the first time a problem tackles all of them jointly on real instances. Moreover, differently from the literature, we treat the unnecessary move operations as soft constraints and analyze their trade-off with the value maximization. As a result, the problem is inherently multi-objective and extremely challenging. We tackle it by proposing a randomized constructive heuristic that iteratively combines items in a preprocessing procedure, sorts them based on multiple criteria, uses randomization to partially perturb the sorting, and finally constructs the packing while complying with all the side constraints. We also propose dual bounds based on CLP relaxations. On large-scale industry instances, our algorithm runs in a few seconds and outperforms (in terms of value and constraints handling) both the solutions constructed manually by the company and those provided by a commercial software. The algorithm is currently used by the company generating significant economic and CO 2 savings.
{"title":"An Optimization Approach for a Complex Real-Life Container Loading Problem","authors":"M. Gajda, Alessio Trivella, R. Mansini, David Pisinger","doi":"10.2139/ssrn.3740046","DOIUrl":"https://doi.org/10.2139/ssrn.3740046","url":null,"abstract":"Abstract We consider a real-world packing problem faced by a logistics company that loads and ships hundreds of trucks every day. For each shipment, the cargo has to be selected from a set of heterogeneous boxes. The goal of the resulting container loading problem (CLP) is to maximize the value of the cargo while satisfying a number of practical constraints to ensure safety and facilitate cargo handling, including customer priorities, load balancing, cargo stability, stacking constraints, positioning constraints, and limiting the number of unnecessary cargo move operations during multi-shipment deliveries. Although some of these constraints have been considered in the literature, this is the first time a problem tackles all of them jointly on real instances. Moreover, differently from the literature, we treat the unnecessary move operations as soft constraints and analyze their trade-off with the value maximization. As a result, the problem is inherently multi-objective and extremely challenging. We tackle it by proposing a randomized constructive heuristic that iteratively combines items in a preprocessing procedure, sorts them based on multiple criteria, uses randomization to partially perturb the sorting, and finally constructs the packing while complying with all the side constraints. We also propose dual bounds based on CLP relaxations. On large-scale industry instances, our algorithm runs in a few seconds and outperforms (in terms of value and constraints handling) both the solutions constructed manually by the company and those provided by a commercial software. The algorithm is currently used by the company generating significant economic and CO 2 savings.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78947783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Jaczkowski, E. Uhlmann, Sven Anders, Waldemar Reder
High-performance materials offer enormous potential for increasing the efficiency of many complex and highly stressed systems in the aerospace industry. However, due to their special material properties, most of these materials are very difficult to machine using conventional machining processes such as turning, milling and drilling. In comparison, water jet cutting technology offers all the prerequisites to bring high-performance materials to their final contour and to efficiently realize a large portion of the material removal. Because of the complex geometry of 3D components used in the aerospace industry, a further development of existing system technology as well as the generation of cutting paths, which are usually designed for pure 2D machining, is required. The aim of the study is the implementation of an automated pre-contouring for difficult to machine materials using abrasive water jet cutting for industrial 3D applications. This is achieved by using an innovative workpiece clamping as well as a new cutting technology, the trimming, in order to reduce the costs of the pre-contouring process as well as the time and resource consumption of the entire process chain. During trimming, a continuous cut takes place and the semi-finished product is brought closer and closer to the required component geometry by cutting off the outer material areas. For this purpose, tests were carried out on workpieces made of stainless steel X5CrNi18 (EN 1.4301) with cutting conditions that are demanding for the abrasive water jet cutting process, such as high cutting depths with simultaneously low cutting angles. It was possible to use these findings to extend existing material models and thus ensure an error-free path generation for cutting processes. The investigations are the basis for the future use of waterjet cutting for near-net-shape machining of workpieces with complex 3D geometry. The experiments showed promising results in terms of the economic efficiency of the trimming process and provide a basis for subsequent investigations with difficult-to-machine workpieces for the aerospace industry.
高性能材料为提高航空航天工业中许多复杂和高压系统的效率提供了巨大的潜力。然而，由于其特殊的材料性能，这些材料中的大多数很难用车削、铣削和钻孔等传统加工工艺进行加工。相比之下，水射流切割技术提供了所有先决条件，使高性能材料达到其最终轮廓，并有效地实现了大部分材料的去除。由于航空航天工业中使用的3D部件具有复杂的几何形状，因此需要进一步发展现有的系统技术以及通常为纯2D加工设计的切削路径的生成。该研究的目的是利用磨料水射流切割实现工业3D应用中难以加工的材料的自动预轮廓。这是通过使用一种创新的工件夹紧以及一种新的切割技术，切边，以减少预成形过程的成本，以及整个工艺链的时间和资源消耗来实现的。在修剪过程中，通过切割外部材料区域，进行连续切割，使半成品越来越接近所需的部件几何形状。为此，对不锈钢X5CrNi18 (EN 1.4301)的工件进行了试验，其切割条件要求磨料水射流切割工艺，如高切割深度同时低切割角度。有可能使用这些发现来扩展现有的材料模型，从而确保切割过程的无误差路径生成。研究结果为今后将水射流切割用于复杂三维几何形状工件的近净形加工奠定了基础。实验结果表明，该铣削工艺在经济效率方面取得了良好的效果，为后续航空航天工业中难加工工件的研究提供了基础。
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Pub Date : 2020-10-30DOI: 10.15587/1729-4061.2020.214995
B. Lanetskii, V. Lukyanchuk, H. Khudov, Mikhail Fisun, Oleksii Zvieriev, I. Terebuha
Solving the problems of setting requirements to the reliability of complex technical systems for various purposes presupposes their classification according to the features characterizing the purpose, modes of use, etc. According to the modes of use, systems are divided into objects of continuous long-term use, repeated cyclic use, and single-use. The objects of repeated cyclic use include the systems operating in cycles. Durations of the periods of work and pause in the cycle are considered deterministic values. Technological and/or technical maintenance is carried out in pauses between the operation periods. In addition to the known classification, it was proposed to introduce a group of systems of repeated use with a complex operating mode. A complex mode is understood as a mode that includes waiting for a request of the system use and executing the request after it arrives at a random time. An analytical model of reliability of such a system has been developed in the form of a ratio for a non-stationary total coefficient of operational readiness. This model describes the processes of the system functioning in the intervals of waiting and use. In this case, the duration of the intervals of waiting and/or execution of the request are random values. Ratios for this indicator were obtained for three options of specifying the functions of distribution of durations of waiting in a turn-on condition and fulfilling the request for use. The developed model makes it possible to set requirements for reliability and maintainability of the systems with a complex operating mode. The results of modeling the dependences of the operational indicators of reliability on parameters of the functions of distribution of durations of waiting and executing the request were obtained for different distributions. Recommendations were formulated concerning the substantiation of the requirements to reliability and maintainability of the systems under consideration
{"title":"Developing the Model of Reliability of a Complex Technical System of Repeated Use with a Complex Operating Mode","authors":"B. Lanetskii, V. Lukyanchuk, H. Khudov, Mikhail Fisun, Oleksii Zvieriev, I. Terebuha","doi":"10.15587/1729-4061.2020.214995","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.214995","url":null,"abstract":"Solving the problems of setting requirements to the reliability of complex technical systems for various purposes presupposes their classification according to the features characterizing the purpose, modes of use, etc. According to the modes of use, systems are divided into objects of continuous long-term use, repeated cyclic use, and single-use. The objects of repeated cyclic use include the systems operating in cycles. Durations of the periods of work and pause in the cycle are considered deterministic values. Technological and/or technical maintenance is carried out in pauses between the operation periods. In addition to the known classification, it was proposed to introduce a group of systems of repeated use with a complex operating mode. A complex mode is understood as a mode that includes waiting for a request of the system use and executing the request after it arrives at a random time. An analytical model of reliability of such a system has been developed in the form of a ratio for a non-stationary total coefficient of operational readiness. This model describes the processes of the system functioning in the intervals of waiting and use. In this case, the duration of the intervals of waiting and/or execution of the request are random values. Ratios for this indicator were obtained for three options of specifying the functions of distribution of durations of waiting in a turn-on condition and fulfilling the request for use. The developed model makes it possible to set requirements for reliability and maintainability of the systems with a complex operating mode. The results of modeling the dependences of the operational indicators of reliability on parameters of the functions of distribution of durations of waiting and executing the request were obtained for different distributions. Recommendations were formulated concerning the substantiation of the requirements to reliability and maintainability of the systems under consideration","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84841105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dedy Ariansyah, A. Buerkle, Ali Al-Yacoub, Melanie Zimmer, J. Erkoyuncu, N. Lohse
Digital twins (DTs) have demonstrated their abilities to integrate sensor data, current state information, and the information about the environment in virtual models. While previous approaches have focused on creating DTs for mainly machines and workstations, a small number of studies have considered human performance when designing the DT system, which leads to a deficiency in overall system performance. The absence of the human integrated-DT framework may decelerate human integration in industrial DT, and thus, disregards the crucial role of the human in the industry of the future. This paper presents a framework for digital human representation in an industrial DT to continuously monitor and to analyse the human operational state and behaviour. Thereby, the DT enables decision-makers to allocate tasks on the shop floor taking into account the human physical and mental status. A sample case showed how a human muscle activity monitoring system could be integrated with the DT based on the developed framework to account for the operator’s muscular fatigue or physical exhaustion for decision-making. This included the use of Artificial Intelligence (AI) to interpret the human activity related data using wearable sensors, such as electromyography (EMG). Future research is proposed to harness human data from a richer variety of sensors as control parameters for production operation and improved decision-making.
{"title":"Towards a Digital Human Representation in an Industrial Digital Twin","authors":"Dedy Ariansyah, A. Buerkle, Ali Al-Yacoub, Melanie Zimmer, J. Erkoyuncu, N. Lohse","doi":"10.2139/ssrn.3717733","DOIUrl":"https://doi.org/10.2139/ssrn.3717733","url":null,"abstract":"Digital twins (DTs) have demonstrated their abilities to integrate sensor data, current state information, and the information about the environment in virtual models. While previous approaches have focused on creating DTs for mainly machines and workstations, a small number of studies have considered human performance when designing the DT system, which leads to a deficiency in overall system performance. The absence of the human integrated-DT framework may decelerate human integration in industrial DT, and thus, disregards the crucial role of the human in the industry of the future. This paper presents a framework for digital human representation in an industrial DT to continuously monitor and to analyse the human operational state and behaviour. Thereby, the DT enables decision-makers to allocate tasks on the shop floor taking into account the human physical and mental status. A sample case showed how a human muscle activity monitoring system could be integrated with the DT based on the developed framework to account for the operator’s muscular fatigue or physical exhaustion for decision-making. This included the use of Artificial Intelligence (AI) to interpret the human activity related data using wearable sensors, such as electromyography (EMG). Future research is proposed to harness human data from a richer variety of sensors as control parameters for production operation and improved decision-making.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"104 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77308847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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