Precise calculation of wave fronts and high-gradient components is always of utmost importance for problems of numerical simulation of wave processes in media and composite structures. The usage mesh algorithms come across specific obstacles, which do not allow to accurately calculate such disturbances localized at the loading area or propagated with time. One of such obstacles (notably in the problems with singularities) is the spurious effect caused by the mesh dispersion responsible for the emergence of high-frequency “parasite” oscillations damaged the computer solution. In this work, advanced numerical algorithms within the explicit finite-difference scheme are developed exactly for very purpose – to precisely calculate wave processes with singularities. The algorithms are constructed with the condition that dependence domains are the same (or maximally closed) in differential and difference equations corresponding to continual and discrete models, respectively. In the designed algorithms, the influence of spurious effects of numerical dispersion is suppressed (or essentially minimized) that allows discontinuities in fronts and high-gradient components to be accurately calculated. A set of examples of computer simulations of linear and nonlinear wave processes are presented. Among them are (a) impact propagation in a waveguide resting on an elastic foundation, (b) cylindrical and spherical waves, and (c) wave propagation and fracture pattern in a unidirectional composite. Comparison of results calculated by conventional and developed algorithms clearly shows the advantage of the latter. To this end, precise numerical solutions (in mesh points of the discrete space) are obtained for the problems listed above.
{"title":"MESH DISPERSION MINIMIZATION ALGORITHMS WITHIN EXPLICIT FINITE-DIFFERENCE SCHEMES TO CALCULATE TRANSIENT WAVE PROCESSES IN ELASTIC MEDIA AND COMPOSITE STRUCTURES","authors":"S. Abdukadirov","doi":"10.2495/cmem210061","DOIUrl":"https://doi.org/10.2495/cmem210061","url":null,"abstract":"Precise calculation of wave fronts and high-gradient components is always of utmost importance for problems of numerical simulation of wave processes in media and composite structures. The usage mesh algorithms come across specific obstacles, which do not allow to accurately calculate such disturbances localized at the loading area or propagated with time. One of such obstacles (notably in the problems with singularities) is the spurious effect caused by the mesh dispersion responsible for the emergence of high-frequency “parasite” oscillations damaged the computer solution. In this work, advanced numerical algorithms within the explicit finite-difference scheme are developed exactly for very purpose – to precisely calculate wave processes with singularities. The algorithms are constructed with the condition that dependence domains are the same (or maximally closed) in differential and difference equations corresponding to continual and discrete models, respectively. In the designed algorithms, the influence of spurious effects of numerical dispersion is suppressed (or essentially minimized) that allows discontinuities in fronts and high-gradient components to be accurately calculated. A set of examples of computer simulations of linear and nonlinear wave processes are presented. Among them are (a) impact propagation in a waveguide resting on an elastic foundation, (b) cylindrical and spherical waves, and (c) wave propagation and fracture pattern in a unidirectional composite. Comparison of results calculated by conventional and developed algorithms clearly shows the advantage of the latter. To this end, precise numerical solutions (in mesh points of the discrete space) are obtained for the problems listed above.","PeriodicalId":406572,"journal":{"name":"Computational Methods and Experimental Measurements XX","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129501737","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}
Madhu Sudan Sapkota, E. Apeh, M. Hadfield, R. Adey, J. Baynham
The process of developing a virtual replica of a physical asset usually involves using standardized parameter values to provide simulation of the physical asset. The parameters of the virtual replica are also continuously validated and updated over time in response to the physical asset’s degradation and changing environmental conditions. The parametric calibration of the simulation models is usually made with trial-and-error using data obtained from manual survey readings of designated parts of the physical asset. Digital Twining (DT) has provided a means by which validating data from the physical asset can be obtained in near real time. However, the time-consuming process of calibrating the parameters so the simulation output of the virtual replica matches the data from physical asset persists. This is even more so when the calibration of the simulator is performed manually by analysing the data received from the physical system using expert knowledge. The manual process of applying domain knowledge to update the parameters is error prone due to incompleteness of the knowledge and inconsistency of the validation/calibration data. To address these shortcomings, an experimental platform implemented by integrating a simulator and a scientific software is proposed. The scientific software provides for the reading and visualisation of the simulation data, automation of the simulation running process and provide interface of the relevant validation and adaptive algorithmics. This comprehensive integrated platform provides an automated online model validation and adaptation environment. The proposed platform is demonstrated using BEASY – a simulator designed to predict protection provided by a cathodic protection (CP) system to an asset, with MATLAB as the scientific software. The developed setup facilitates the task of model validation and adaptation of the CP model by automating the process within a DT ecosystem.
{"title":"DESIGN OF EXPERIMENTS PLATFORM FOR ONLINE SIMULATION MODEL VALIDATION AND PARAMETER UPDATING WITHIN DIGITAL TWINNING","authors":"Madhu Sudan Sapkota, E. Apeh, M. Hadfield, R. Adey, J. Baynham","doi":"10.2495/cmem210011","DOIUrl":"https://doi.org/10.2495/cmem210011","url":null,"abstract":"The process of developing a virtual replica of a physical asset usually involves using standardized parameter values to provide simulation of the physical asset. The parameters of the virtual replica are also continuously validated and updated over time in response to the physical asset’s degradation and changing environmental conditions. The parametric calibration of the simulation models is usually made with trial-and-error using data obtained from manual survey readings of designated parts of the physical asset. Digital Twining (DT) has provided a means by which validating data from the physical asset can be obtained in near real time. However, the time-consuming process of calibrating the parameters so the simulation output of the virtual replica matches the data from physical asset persists. This is even more so when the calibration of the simulator is performed manually by analysing the data received from the physical system using expert knowledge. The manual process of applying domain knowledge to update the parameters is error prone due to incompleteness of the knowledge and inconsistency of the validation/calibration data. To address these shortcomings, an experimental platform implemented by integrating a simulator and a scientific software is proposed. The scientific software provides for the reading and visualisation of the simulation data, automation of the simulation running process and provide interface of the relevant validation and adaptive algorithmics. This comprehensive integrated platform provides an automated online model validation and adaptation environment. The proposed platform is demonstrated using BEASY – a simulator designed to predict protection provided by a cathodic protection (CP) system to an asset, with MATLAB as the scientific software. The developed setup facilitates the task of model validation and adaptation of the CP model by automating the process within a DT ecosystem.","PeriodicalId":406572,"journal":{"name":"Computational Methods and Experimental Measurements XX","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123926890","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. Marcelli, Francesco Manfredi Frattarelli, V. Piermattei, S. Scanu, S. Bonamano, D. Piazzolla, G. Zappalà
The coastal zone is characterised by diversified physical and ecological conditions that allow the multiple use of natural resources. The overlap of very different uses generates conflict inducing habitat depletion and damage to natural systems. To face the problem of “conflict of use” of the coastal areas, we developed an integrated system as a working tool, the Sea Use Map (SUM), aimed to the characterization of the different values and uses of the marine resource, useful to explore further marine uses, such as suitable sites for marine renewable energy production, productive activities, etc. For this reason, the creation of an integrated GIS database, in which the information is conveyed in a geo-referenced system, is the necessary tool to support maritime spatial planning. The SUM of Italy is a key database, in which coastal uses are integrated with environmental data (seabed morphology, waves, currents, fauna, flora, etc.). Further integration between data and simulations of numerical models allows to define the most promising and ecologically acceptable areas for the introduction of new uses in view of the compatible development of the sea and marine resources. This paper presents a pilot application study in the coastal area between Capo Anzio and Tarquinia (Italy, Latium).
{"title":"SEA USE MAP: GIS SUPPORTING MARINE AREA’S SUSTAINABLE DEVELOPMENT","authors":"M. Marcelli, Francesco Manfredi Frattarelli, V. Piermattei, S. Scanu, S. Bonamano, D. Piazzolla, G. Zappalà","doi":"10.2495/cmem210021","DOIUrl":"https://doi.org/10.2495/cmem210021","url":null,"abstract":"The coastal zone is characterised by diversified physical and ecological conditions that allow the multiple use of natural resources. The overlap of very different uses generates conflict inducing habitat depletion and damage to natural systems. To face the problem of “conflict of use” of the coastal areas, we developed an integrated system as a working tool, the Sea Use Map (SUM), aimed to the characterization of the different values and uses of the marine resource, useful to explore further marine uses, such as suitable sites for marine renewable energy production, productive activities, etc. For this reason, the creation of an integrated GIS database, in which the information is conveyed in a geo-referenced system, is the necessary tool to support maritime spatial planning. The SUM of Italy is a key database, in which coastal uses are integrated with environmental data (seabed morphology, waves, currents, fauna, flora, etc.). Further integration between data and simulations of numerical models allows to define the most promising and ecologically acceptable areas for the introduction of new uses in view of the compatible development of the sea and marine resources. This paper presents a pilot application study in the coastal area between Capo Anzio and Tarquinia (Italy, Latium).","PeriodicalId":406572,"journal":{"name":"Computational Methods and Experimental Measurements XX","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123354192","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}
Establishing the actual gear root bending strength is a fundamental aspect in gear design. With this respect, gears materials can be characterized through two types of tests, i.e. on Running Gears (RG) or Single Tooth Bending Fatigue (STBF). The former is able to reproduce the loading conditions of the actual gears and, therefore, leads to the most accurate results. The latter excels in terms of efficiency and simplicity of the experimental campaign but as a drawback, tends usually to overestimate the material strength due to the different stress state histories it induces on the tooth root. Therefore, a common practice is to carry out STBF tests and apply a correction coefficient (f ) for exploiting the results in the design of actual gears. In the present paper, an approach to estimate f centered on the combination of numerical simulations and multi-axial fatigue criteria based on the critical plane capable of taking into account non-proportional loading conditions has been proposed. In particular, the same gear geometry has been simulated through Finite Element (FE) models in two conditions, i.e. STBF and RG. The outcomes of the simulations, in terms of stress histories in the tooth root region, have been analyzed with five different fatigue criteria, i.e. Findley, Matake, McDiarmid, Papadopoulos, and Susmel et al. f has been calculated as the ratio between the maximum damage parameter observed in the STBF and RG conditions according to the different fatigue criteria. Results show that f , calculated for three different materials (i.e. 18NiCrMo5, 42CrMoS4, 31CrMo12), differs up to 22% between the RG and the STBF conditions (depending on the criterion considered). Therefore, future studies should aim to understand which fatigue criterion is the most appropriate for this type of analysis.
{"title":"RELIABLE GEAR DESIGN: TRANSLATION OF THE RESULTS OF SINGLE TOOTH BENDING FATIGUE TESTS THROUGH THE COMBINATION OF NUMERICAL SIMULATIONS AND FATIGUE CRITERIA","authors":"F. Concli, L. Maccioni, L. Bonaiti","doi":"10.2495/cmem210101","DOIUrl":"https://doi.org/10.2495/cmem210101","url":null,"abstract":"Establishing the actual gear root bending strength is a fundamental aspect in gear design. With this respect, gears materials can be characterized through two types of tests, i.e. on Running Gears (RG) or Single Tooth Bending Fatigue (STBF). The former is able to reproduce the loading conditions of the actual gears and, therefore, leads to the most accurate results. The latter excels in terms of efficiency and simplicity of the experimental campaign but as a drawback, tends usually to overestimate the material strength due to the different stress state histories it induces on the tooth root. Therefore, a common practice is to carry out STBF tests and apply a correction coefficient (f ) for exploiting the results in the design of actual gears. In the present paper, an approach to estimate f centered on the combination of numerical simulations and multi-axial fatigue criteria based on the critical plane capable of taking into account non-proportional loading conditions has been proposed. In particular, the same gear geometry has been simulated through Finite Element (FE) models in two conditions, i.e. STBF and RG. The outcomes of the simulations, in terms of stress histories in the tooth root region, have been analyzed with five different fatigue criteria, i.e. Findley, Matake, McDiarmid, Papadopoulos, and Susmel et al. f has been calculated as the ratio between the maximum damage parameter observed in the STBF and RG conditions according to the different fatigue criteria. Results show that f , calculated for three different materials (i.e. 18NiCrMo5, 42CrMoS4, 31CrMo12), differs up to 22% between the RG and the STBF conditions (depending on the criterion considered). Therefore, future studies should aim to understand which fatigue criterion is the most appropriate for this type of analysis.","PeriodicalId":406572,"journal":{"name":"Computational Methods and Experimental Measurements XX","volume":"132 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129967107","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. Goto, Takahito Utsunomiya, Takaei Yamamoto, Seung-Zeon Han, J. Kitamura, J. Ahn, Sung-Hwan Lim, T. Yakushiji
Microstructure and fatigue properties of Cu–6Ni–1.5Si alloy having different morphologies of Ni2Si intermetallic compounds that are disk-shaped continuous precipitates (CPs) with nano-size diameter by normal aging, fibre-shaped discontinuous precipitates (DPs) by overaging and elongated DPs fabricated by cold-rolling (DPR) were studied. There was a negligible difference in fatigue strength between the CP and DP specimens despite higher tensile strength of the CP specimen. The DPR specimen had the highest tensile and fatigue strengths in all specimens. The fatigue crack initiation resistance of the DPR specimen was drastically enhanced. The growth rate of a small crack can be determined by a term σanl. The crack growth resistance of the DPR specimen was nearly equal to that of the CP specimen. The reason for such trends of tensile and fatigue strengths was discussed based on the microstructure of each specimen.
{"title":"MICROSTRUCTURE AND FATIGUE PROPERTIES OF CU–NI–SI ALLOY STRENGTHENED BY NI2SI INTERMETALLIC COMPOUNDS","authors":"M. Goto, Takahito Utsunomiya, Takaei Yamamoto, Seung-Zeon Han, J. Kitamura, J. Ahn, Sung-Hwan Lim, T. Yakushiji","doi":"10.2495/cmem210071","DOIUrl":"https://doi.org/10.2495/cmem210071","url":null,"abstract":"Microstructure and fatigue properties of Cu–6Ni–1.5Si alloy having different morphologies of Ni2Si intermetallic compounds that are disk-shaped continuous precipitates (CPs) with nano-size diameter by normal aging, fibre-shaped discontinuous precipitates (DPs) by overaging and elongated DPs fabricated by cold-rolling (DPR) were studied. There was a negligible difference in fatigue strength between the CP and DP specimens despite higher tensile strength of the CP specimen. The DPR specimen had the highest tensile and fatigue strengths in all specimens. The fatigue crack initiation resistance of the DPR specimen was drastically enhanced. The growth rate of a small crack can be determined by a term σanl. The crack growth resistance of the DPR specimen was nearly equal to that of the CP specimen. The reason for such trends of tensile and fatigue strengths was discussed based on the microstructure of each specimen.","PeriodicalId":406572,"journal":{"name":"Computational Methods and Experimental Measurements XX","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116146859","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. A. Marquez, C. A. M. Santos, H. Mollinedo, Judith Diaz Dominguez, J. Hernández
In the study of mechanical properties of materials the microstructure of a material is usually subjected to some kind of homogenization; however, there are materials in which the microstructural disorder must be considered. This disorder manifests itself in the fracture resistance of materials. Some empirical experimental studies and various types of models (based on variations in mass per unit area) have been made to relate the effect of the disorder during crack propagation with the macroscopic resistance of the material, but the absolute-density/mass projections have not been a good descriptor to extrapolate the behavior of the material between its microstructure and the macroscale since it is difficult to determine the porosity and the net trajectory of the fibers. The physical phenomenon of the instability of the crack propagation of interest in the present work occurs on a meso-scale, where the microstructure of the materials can be characterized only statistically and has been established as the range in which the bridge can exist between the micro and macro behavior of this kind of materials. By the Digital Image Correlation Technique the crack propagation is followed based on the displacements produced locally by the arrangement of the fibers in front of the crack tip of paper, as a material model. At the beginning of the load process is observed a smooth trace in the peak local deformation corresponding with the elastic part of the stress-curve; after, when the stress-curve starts to deflect, the peak local-deformation trace change in its slope and it becomes intermittent, this behavior is attributed to the local conditions of material. Finally, it observed that the local deformation is a good descriptor for the crack extension.
{"title":"CHARACTERIZATION OF THE CRACK PROPAGATION IN A MICROSTRUCTURALLY RANDOM MATERIAL","authors":"M. A. Marquez, C. A. M. Santos, H. Mollinedo, Judith Diaz Dominguez, J. Hernández","doi":"10.2495/cmem210111","DOIUrl":"https://doi.org/10.2495/cmem210111","url":null,"abstract":"In the study of mechanical properties of materials the microstructure of a material is usually subjected to some kind of homogenization; however, there are materials in which the microstructural disorder must be considered. This disorder manifests itself in the fracture resistance of materials. Some empirical experimental studies and various types of models (based on variations in mass per unit area) have been made to relate the effect of the disorder during crack propagation with the macroscopic resistance of the material, but the absolute-density/mass projections have not been a good descriptor to extrapolate the behavior of the material between its microstructure and the macroscale since it is difficult to determine the porosity and the net trajectory of the fibers. The physical phenomenon of the instability of the crack propagation of interest in the present work occurs on a meso-scale, where the microstructure of the materials can be characterized only statistically and has been established as the range in which the bridge can exist between the micro and macro behavior of this kind of materials. By the Digital Image Correlation Technique the crack propagation is followed based on the displacements produced locally by the arrangement of the fibers in front of the crack tip of paper, as a material model. At the beginning of the load process is observed a smooth trace in the peak local deformation corresponding with the elastic part of the stress-curve; after, when the stress-curve starts to deflect, the peak local-deformation trace change in its slope and it becomes intermittent, this behavior is attributed to the local conditions of material. Finally, it observed that the local deformation is a good descriptor for the crack extension.","PeriodicalId":406572,"journal":{"name":"Computational Methods and Experimental Measurements XX","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116615113","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}
Additive Manufacturing (AM) is becoming a more and more widespread (and trendy) approach. Its flexibility and capability to manufacture any topology has opened new possibilities: AM could lead to significant performance improvements thanks to the exploitation of lattice or reticular structures as partial replacement of the traditional solid design. The potential of this technology knows no bounds. However, in the real world, the lower performances of the materials and the high manufacturing costs significantly restrict the fields of application for which the adoption of AM results effective. In this context, the mechanical static and fatigue properties of a 17-4 PH Stainless Steel produced via AM were experimentally measured and compared with those of the wrought material to quantify the performance reduction. Based on these data, three components, namely a hip prosthesis, a blow plastic bottle die, and an automotive gear were selected as representative examples to show the pros and contra of AM. The three components were chosen because they belong to three quite dissimilar fields and are produced in different batch sizes. The three original designs were specifically optimized for AM by means of Finite Element (FE) Simulations. The new solutions fulfil the strength requirements of the original parts showing at the same time reduced weights and inertias. The traditional and new designs were compared in terms of production times and costs to quantify the real benefits of AM for different applications.
{"title":"DESIGN FOR ADDITIVE MANUFACTURING: IS IT AN EFFECTIVE ALTERNATIVE? PART 2 – COST EVALUATION","authors":"F. Concli, Margherita Molinaro, Eleonora Rampazzo","doi":"10.2495/cmem210091","DOIUrl":"https://doi.org/10.2495/cmem210091","url":null,"abstract":"Additive Manufacturing (AM) is becoming a more and more widespread (and trendy) approach. Its flexibility and capability to manufacture any topology has opened new possibilities: AM could lead to significant performance improvements thanks to the exploitation of lattice or reticular structures as partial replacement of the traditional solid design. The potential of this technology knows no bounds. However, in the real world, the lower performances of the materials and the high manufacturing costs significantly restrict the fields of application for which the adoption of AM results effective. In this context, the mechanical static and fatigue properties of a 17-4 PH Stainless Steel produced via AM were experimentally measured and compared with those of the wrought material to quantify the performance reduction. Based on these data, three components, namely a hip prosthesis, a blow plastic bottle die, and an automotive gear were selected as representative examples to show the pros and contra of AM. The three components were chosen because they belong to three quite dissimilar fields and are produced in different batch sizes. The three original designs were specifically optimized for AM by means of Finite Element (FE) Simulations. The new solutions fulfil the strength requirements of the original parts showing at the same time reduced weights and inertias. The traditional and new designs were compared in terms of production times and costs to quantify the real benefits of AM for different applications.","PeriodicalId":406572,"journal":{"name":"Computational Methods and Experimental Measurements XX","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124212498","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}
Modeling, simulating, and analyzing turbulent flow is a topic of high interest from both a verification and accuracy aspect. This work presents computational methods and experimental measures of turbulent fluid flow modeled with particle-based smoothed particle hydrodynamics (SPH), as well as the use of second-generation wavelets to analyze the nature of vorticity. Modeling and analyzing vorticity by use of first-generation wavelets for regular grid methods are well presented in literature. We are unaware of any work on this topic for particle-based methods. The difference between regular grid-based and particle-based approaches are due to irregularities introduced by the latter. We found that secondgeneration wavelets proved to be robust, fast, and reliable. Second-generation wavelets are designed to handle irregular grids and do not rely on a dyadic number of observations, which make them suitable candidates for SPH analysis as opposed to first generation wavelets. The resulting significant discrete wavelet transform (DWT) coefficients are found to be representative of the flow sections that may benefit from additional attention in the simulation model. The robustness of the method allows for fast initial screening of the flow to highlight sections that are of interest for more detailed analysis. Here, robustness refers to the two parameters significance level and grid resolution. Our results are demonstrated using a 2D sloshing tank case.
{"title":"PARTICLE-BASED FLOW VORTICITY ANALYSIS BY USE OF SECOND-GENERATION WAVELETS","authors":"Oddny Brun, Joseph T. Kider, R. Wiegand","doi":"10.2495/cmem210051","DOIUrl":"https://doi.org/10.2495/cmem210051","url":null,"abstract":"Modeling, simulating, and analyzing turbulent flow is a topic of high interest from both a verification and accuracy aspect. This work presents computational methods and experimental measures of turbulent fluid flow modeled with particle-based smoothed particle hydrodynamics (SPH), as well as the use of second-generation wavelets to analyze the nature of vorticity. Modeling and analyzing vorticity by use of first-generation wavelets for regular grid methods are well presented in literature. We are unaware of any work on this topic for particle-based methods. The difference between regular grid-based and particle-based approaches are due to irregularities introduced by the latter. We found that secondgeneration wavelets proved to be robust, fast, and reliable. Second-generation wavelets are designed to handle irregular grids and do not rely on a dyadic number of observations, which make them suitable candidates for SPH analysis as opposed to first generation wavelets. The resulting significant discrete wavelet transform (DWT) coefficients are found to be representative of the flow sections that may benefit from additional attention in the simulation model. The robustness of the method allows for fast initial screening of the flow to highlight sections that are of interest for more detailed analysis. Here, robustness refers to the two parameters significance level and grid resolution. Our results are demonstrated using a 2D sloshing tank case.","PeriodicalId":406572,"journal":{"name":"Computational Methods and Experimental Measurements XX","volume":"24 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120986470","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}
Within the rapid growth of the energy demand of buildings, cities start to look at ways to shift towards more sustainable solutions that seek the reduction of energy consumption. In the last few decades, Egypt has witnessed a high rate of residential sector investments to accommodate the population inflation. As a result, such buildings in the residential sector consume the highest rates of energy exhaustion to meet the requirements of heating, cooling, and lighting; with the largest amount of burdens, the environment has to afford. Consequently, it is essential to consider energy control and careful analysis of environmental impacts as an essential part of the design of residential buildings. Life Cycle Assessment has gained significant attention in the study of energy control. It helps to analyze the energy patterns and environmental impacts of every single parameter engaged in the design of buildings. However, its complexity limits its integration into the conventional design process. Which lead to the need of engaging computer-aided design techniques and parametric approaches for the easiness of application. This research aims at developing a framework that achieves a reasonable integration between LCA and the traditional design process focusing on early design stages. It provides architects and designers with a structured methodology that enables them to achieve sustainability goals in their designs. The study follows a framework that firstly examines previous research on LCA. Secondly, it highlights the early design decisions and measures their effect on the final output using parametric tools. Lastly, it examines the validation of the developed framework by the implementation of a selected case study. This helps to carry out design optimization based on LCA in the design process.
{"title":"OPTIMIZING A LIFE CYCLE ASSESSMENT-BASED DESIGN DECISION SUPPORT SYSTEM TOWARDS ECO-CONSCIOUS ARCHITECTURE","authors":"Mahmoud Gomaa, Tarek A. Farghaly, Z. E. Sayad","doi":"10.2495/cmem210041","DOIUrl":"https://doi.org/10.2495/cmem210041","url":null,"abstract":"Within the rapid growth of the energy demand of buildings, cities start to look at ways to shift towards more sustainable solutions that seek the reduction of energy consumption. In the last few decades, Egypt has witnessed a high rate of residential sector investments to accommodate the population inflation. As a result, such buildings in the residential sector consume the highest rates of energy exhaustion to meet the requirements of heating, cooling, and lighting; with the largest amount of burdens, the environment has to afford. Consequently, it is essential to consider energy control and careful analysis of environmental impacts as an essential part of the design of residential buildings. Life Cycle Assessment has gained significant attention in the study of energy control. It helps to analyze the energy patterns and environmental impacts of every single parameter engaged in the design of buildings. However, its complexity limits its integration into the conventional design process. Which lead to the need of engaging computer-aided design techniques and parametric approaches for the easiness of application. This research aims at developing a framework that achieves a reasonable integration between LCA and the traditional design process focusing on early design stages. It provides architects and designers with a structured methodology that enables them to achieve sustainability goals in their designs. The study follows a framework that firstly examines previous research on LCA. Secondly, it highlights the early design decisions and measures their effect on the final output using parametric tools. Lastly, it examines the validation of the developed framework by the implementation of a selected case study. This helps to carry out design optimization based on LCA in the design process.","PeriodicalId":406572,"journal":{"name":"Computational Methods and Experimental Measurements XX","volume":"216 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130646563","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}
Additive manufacturing (AM) is becoming a more and more widespread (and trendy) approach. Its flexibility and capability to manufacture any topology has opened new possibilities: AM could lead to significant performance improvements thanks to the exploitation of lattice or reticular structures as partial replacement of the traditional solid design. The potential of this technology knows no bounds. However, in the real world, the lower performances of the materials and the high manufacturing costs significantly restrict the fields of application for which the adoption of AM results effective. In this context, the mechanical static and fatigue properties of a 17-4 PH stainless steel produced via AM were experimentally measured and compared with those of the wrought material to quantify the performance reduction. Based on these data, three components, namely a hip prosthesis, a blow plastic bottle die, and an automotive gear were selected as representative examples to show the pros and contra of AM. The three components were chosen because they belong to three quite dissimilar fields and are produced in different batch sizes. The three original designs were specifically optimized for AM by means of finite element (FE) simulations. The new solutions fulfil the strength requirements of the original parts showing at the same time reduced weights and inertias. The traditional and new designs were compared in terms of production times and costs to quantify the real benefits of AM for different applications.
{"title":"DESIGN FOR ADDITIVE MANUFACTURING: IS IT AN EFFECTIVE ALTERNATIVE? PART 1 – MATERIAL CHARACTERIZATION AND GEOMETRICAL OPTIMIZATION","authors":"F. Concli, Margherita Molinaro, Eleonora Rampazzo","doi":"10.2495/cmem210081","DOIUrl":"https://doi.org/10.2495/cmem210081","url":null,"abstract":"Additive manufacturing (AM) is becoming a more and more widespread (and trendy) approach. Its flexibility and capability to manufacture any topology has opened new possibilities: AM could lead to significant performance improvements thanks to the exploitation of lattice or reticular structures as partial replacement of the traditional solid design. The potential of this technology knows no bounds. However, in the real world, the lower performances of the materials and the high manufacturing costs significantly restrict the fields of application for which the adoption of AM results effective. In this context, the mechanical static and fatigue properties of a 17-4 PH stainless steel produced via AM were experimentally measured and compared with those of the wrought material to quantify the performance reduction. Based on these data, three components, namely a hip prosthesis, a blow plastic bottle die, and an automotive gear were selected as representative examples to show the pros and contra of AM. The three components were chosen because they belong to three quite dissimilar fields and are produced in different batch sizes. The three original designs were specifically optimized for AM by means of finite element (FE) simulations. The new solutions fulfil the strength requirements of the original parts showing at the same time reduced weights and inertias. The traditional and new designs were compared in terms of production times and costs to quantify the real benefits of AM for different applications.","PeriodicalId":406572,"journal":{"name":"Computational Methods and Experimental Measurements XX","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123205715","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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