Pub Date : 2024-05-15DOI: 10.21741/9781644903131-252
Henning Peters
Abstract. In multi-stage bending and straightening operations cross-stage and quantity-dependent effects crucially affect the quality of the end product. Using punch-bending units in combination with a mechatronic straightening device can improve the accuracy and repeatability of product features remarkably well. In this work a concept for an innovative hybrid model of a roll straightener in a multi-stage straightening and multi-stage bending process is proposed. This model combines data-driven elements with expert knowledge and aims to minimise residual errors of the roll straightener to reliably decrease the risk of disadvantageous cross-stage and quantity-dependent effects on a subsequent punch-bending process.
{"title":"Novel approach for data-driven modelling of multi-stage straightening and bending processes","authors":"Henning Peters","doi":"10.21741/9781644903131-252","DOIUrl":"https://doi.org/10.21741/9781644903131-252","url":null,"abstract":"Abstract. In multi-stage bending and straightening operations cross-stage and quantity-dependent effects crucially affect the quality of the end product. Using punch-bending units in combination with a mechatronic straightening device can improve the accuracy and repeatability of product features remarkably well. In this work a concept for an innovative hybrid model of a roll straightener in a multi-stage straightening and multi-stage bending process is proposed. This model combines data-driven elements with expert knowledge and aims to minimise residual errors of the roll straightener to reliably decrease the risk of disadvantageous cross-stage and quantity-dependent effects on a subsequent punch-bending process.","PeriodicalId":515987,"journal":{"name":"Materials Research Proceedings","volume":"33 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140975558","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 : 2024-05-15DOI: 10.21741/9781644903131-160
Ali Beigzadeh
Abstract. The paper introduces an innovative Incremental Forming (IF) machine, termed "FlexRoll Bending," designed for flexible sheet forming on straight components. Unlike traditional processes, this machine employs two working rollers that can move along three directions and rotate, eliminating the need for specific dies. The study focuses on an "on-edge forming strategy" to manufacture non-uniform cross-section sheet metal parts, presenting a cost-effective alternative to conventional methods. The experimental setup utilizes a 0.8 mm DD11 steel sheet, and a novel toolpath theory is introduced for calculating the movement of the forming rollers. Numerical simulations in LS-DYNA software assess the impact of different toolpaths on the final geometry, revealing successful part manufacturing without defects using a linear toolpath and identifying wrinkling in a two-stage toolpath. The results demonstrate the potential of the FlexRoll Bending process for die-less manufacturing of complex geometry sheet metal parts with low forming forces.
{"title":"Tool path effects on wrinkling in metal sheet incremental roll profiling","authors":"Ali Beigzadeh","doi":"10.21741/9781644903131-160","DOIUrl":"https://doi.org/10.21741/9781644903131-160","url":null,"abstract":"Abstract. The paper introduces an innovative Incremental Forming (IF) machine, termed \"FlexRoll Bending,\" designed for flexible sheet forming on straight components. Unlike traditional processes, this machine employs two working rollers that can move along three directions and rotate, eliminating the need for specific dies. The study focuses on an \"on-edge forming strategy\" to manufacture non-uniform cross-section sheet metal parts, presenting a cost-effective alternative to conventional methods. The experimental setup utilizes a 0.8 mm DD11 steel sheet, and a novel toolpath theory is introduced for calculating the movement of the forming rollers. Numerical simulations in LS-DYNA software assess the impact of different toolpaths on the final geometry, revealing successful part manufacturing without defects using a linear toolpath and identifying wrinkling in a two-stage toolpath. The results demonstrate the potential of the FlexRoll Bending process for die-less manufacturing of complex geometry sheet metal parts with low forming forces.","PeriodicalId":515987,"journal":{"name":"Materials Research Proceedings","volume":"135 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140977185","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 : 2024-05-15DOI: 10.21741/9781644903131-148
Matthias Riemer
Abstract. Data-driven process monitoring is an approach in the field of forming technology for increasing process efficiency. In shear cutting processes surrogate models based on process force signals can be used for process monitoring. Currently, the data basis for developing such models has to be generated within experiments. The generation of synthetic training data using numerical methods seems to be a more efficient alternative approach. In this work, it is investigated whether virtual training data for the prediction of material properties can be generated by numerical methods. An FE model of the investigated shear cutting process has been designed and validated based on experiments. It is shown that especially the consideration of the tool stiffness has a significant influence on the simulated process force signal. The validated FE model is used to generate synthetic training data. Based on this data, different prediction models are trained to predict the material model parameters based on the force signals. Different model types are compared and the hyperparameters are optimized for the preferred model.
摘要数据驱动的过程监控是成形技术领域提高过程效率的一种方法。在剪切切割工艺中，基于工艺力信号的代用模型可用于工艺监控。目前，开发此类模型的数据基础必须在实验中生成。使用数值方法生成合成训练数据似乎是一种更有效的替代方法。在这项工作中，我们研究了是否可以通过数值方法生成用于预测材料特性的虚拟训练数据。在实验的基础上，设计并验证了所研究的剪切切割过程的有限元模型。结果表明，刀具刚度对模拟过程力信号的影响尤为显著。经过验证的 FE 模型用于生成合成训练数据。在这些数据的基础上，对不同的预测模型进行训练，以根据力信号预测材料模型参数。对不同类型的模型进行比较，并对首选模型的超参数进行优化。
{"title":"Shear cutting: Model-based prediction of material parameters based on synthetic process force signals","authors":"Matthias Riemer","doi":"10.21741/9781644903131-148","DOIUrl":"https://doi.org/10.21741/9781644903131-148","url":null,"abstract":"Abstract. Data-driven process monitoring is an approach in the field of forming technology for increasing process efficiency. In shear cutting processes surrogate models based on process force signals can be used for process monitoring. Currently, the data basis for developing such models has to be generated within experiments. The generation of synthetic training data using numerical methods seems to be a more efficient alternative approach. In this work, it is investigated whether virtual training data for the prediction of material properties can be generated by numerical methods. An FE model of the investigated shear cutting process has been designed and validated based on experiments. It is shown that especially the consideration of the tool stiffness has a significant influence on the simulated process force signal. The validated FE model is used to generate synthetic training data. Based on this data, different prediction models are trained to predict the material model parameters based on the force signals. Different model types are compared and the hyperparameters are optimized for the preferred model.","PeriodicalId":515987,"journal":{"name":"Materials Research Proceedings","volume":" 30","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141127951","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 : 2024-05-15DOI: 10.21741/9781644903131-16
Mohamed Khalil Homrani
Abstract. Material Extrusion (MEX) and by extension Fused Deposition Modeling (FDM) is a popular Additive Manufacturing (AM) process used to fabricate complex parts. FDM as of recent is no longer solely utilized for prototyping parts but also used for producing functional components in industrial and research applications. The investigation of material properties of these FDM parts by experimental means is a time-consuming task. Therefore, the use of numerical simulation methods is highly required. Since 1993, various Finite Element Analysis (FEA) models are found in literature attempting to effectively simulate FDM parts utilizing many formulations, each with their pros and cons. The present study aims to compare Lagrangian and Arbitrary Lagrangian-Eulerian (ALE) finite element formulations in simulating tensile loading for FDM parts. The efficiency and precision of the aforementioned methods is evaluated in the numerical simulation of the tensile loading of an ASTM D638 standard geometry ABS specimen utilizing both ABAQUS/Explicit and ABAQUS/Standard. Utilizing a paper from the literature for experimental validation, this study additionally provides insight into explicit and implicit models’ computational efficiency, focusing on the advantages of explicit models for this application. The effects of mesh element type and size on results are also studied for each method. Based on these results, some useful guidelines for selecting the most suitable model of tensile loaded FDM parts are presented.
{"title":"Comparison between ALE and Lagrangian finite element formulations to simulate tensile loading for FDM parts","authors":"Mohamed Khalil Homrani","doi":"10.21741/9781644903131-16","DOIUrl":"https://doi.org/10.21741/9781644903131-16","url":null,"abstract":"Abstract. Material Extrusion (MEX) and by extension Fused Deposition Modeling (FDM) is a popular Additive Manufacturing (AM) process used to fabricate complex parts. FDM as of recent is no longer solely utilized for prototyping parts but also used for producing functional components in industrial and research applications. The investigation of material properties of these FDM parts by experimental means is a time-consuming task. Therefore, the use of numerical simulation methods is highly required. Since 1993, various Finite Element Analysis (FEA) models are found in literature attempting to effectively simulate FDM parts utilizing many formulations, each with their pros and cons. The present study aims to compare Lagrangian and Arbitrary Lagrangian-Eulerian (ALE) finite element formulations in simulating tensile loading for FDM parts. The efficiency and precision of the aforementioned methods is evaluated in the numerical simulation of the tensile loading of an ASTM D638 standard geometry ABS specimen utilizing both ABAQUS/Explicit and ABAQUS/Standard. Utilizing a paper from the literature for experimental validation, this study additionally provides insight into explicit and implicit models’ computational efficiency, focusing on the advantages of explicit models for this application. The effects of mesh element type and size on results are also studied for each method. Based on these results, some useful guidelines for selecting the most suitable model of tensile loaded FDM parts are presented.","PeriodicalId":515987,"journal":{"name":"Materials Research Proceedings","volume":"67 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140971937","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 : 2024-05-15DOI: 10.21741/9781644903131-267
Majid Kavousi
Abstract. This paper presents a methodology to establish a process-structure-property (PSP) relationship for the additive manufacturing (AM) of small AISI 316L parts, as might be used in coronary stent applications. The methodology includes a physically based process-structure model based on cellular automata (CA) for microstructure characterization and generation, coupled with crystal plasticity finite element (CPFE) structure-property modelling to predict the mechanical response of the AM part under tensile loading. The effect of AM process variables, such as laser power and scanning speed, are reflected in the PSP modelling through the thermal modelling of AM feeding into the CA model. The CA method is shown to be able to capture microstructure texture, which is key to anisotropic behavior of AM parts. The present study aims to (i) establish a practical link between CA and CPFE models and (ii) identify optimal process variables with respect to ductility.
摘要本文介绍了一种为冠状动脉支架应用中的小型 AISI 316L 零件的增材制造（AM）建立工艺-结构-性能（PSP）关系的方法。该方法包括一个基于细胞自动机（CA）的物理工艺-结构模型，用于微观结构的表征和生成，并结合晶体塑性有限元（CPFE）结构-属性建模，以预测 AM 零件在拉伸载荷下的机械响应。通过将 AM 热建模输入 CA 模型，PSP 建模反映了 AM 过程变量（如激光功率和扫描速度）的影响。CA 方法能够捕捉微观结构纹理，而微观结构纹理是 AM 零件各向异性行为的关键。本研究旨在（i）建立 CA 模型与 CPFE 模型之间的实用联系，（ii）确定延展性方面的最佳工艺变量。
{"title":"Cellular automata and crystal plasticity modelling for metal additive manufacturing","authors":"Majid Kavousi","doi":"10.21741/9781644903131-267","DOIUrl":"https://doi.org/10.21741/9781644903131-267","url":null,"abstract":"Abstract. This paper presents a methodology to establish a process-structure-property (PSP) relationship for the additive manufacturing (AM) of small AISI 316L parts, as might be used in coronary stent applications. The methodology includes a physically based process-structure model based on cellular automata (CA) for microstructure characterization and generation, coupled with crystal plasticity finite element (CPFE) structure-property modelling to predict the mechanical response of the AM part under tensile loading. The effect of AM process variables, such as laser power and scanning speed, are reflected in the PSP modelling through the thermal modelling of AM feeding into the CA model. The CA method is shown to be able to capture microstructure texture, which is key to anisotropic behavior of AM parts. The present study aims to (i) establish a practical link between CA and CPFE models and (ii) identify optimal process variables with respect to ductility.","PeriodicalId":515987,"journal":{"name":"Materials Research Proceedings","volume":"42 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140973392","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 : 2024-05-15DOI: 10.21741/9781644903131-212
P. Damm
Abstract. The increasing demand for low surface roughness and long service life in highly loaded components, such as extruder shafts, requires high strength, functional reliability and long-term durability. Extruder shafts are applied in plastics technology and in the food industry for processing plastic melts, mixing and compounding. Screw and kneading elements are required for this purpose. The screw and kneading elements are pushed form-fittingly onto a splined shaft. The torque is transmitted by the splined shaft. [1] Main causes of wear and damage of extruder shafts are corrosion and mechanical load. High surface qualities, increased residual compressive stresses and increased surface hardness are possibilities to increase the durability of the splined shafts. These desired properties can be achieved by applying the ball burnishing technology. [2] By utilizing cold working processes, such as ball burnishing, it is possible to enhance the surface and subsurface properties to increase the lifespan of rotary components intended for transmitting high rotational torques. Due to the importance of considering the roughness of the initial surface, this study aimed to generate various roughness and surface profiles through the turning process to investigate their influence on the burnishing process results. For this purpose, shaft sections made of AISI H11 steel were pre-machined with different cutting inserts in order to set different surface roughnesses. Subsequently, a statistical experimental design was created by using the Taguchi method by varying feed rate, pressure and speed. As a main result, roughness and residual stresses on the surface were measured and compared with the initial conditions.
{"title":"Analysis of the influence of the initial surface integrity on the result of burnished high torque splined shafts","authors":"P. Damm","doi":"10.21741/9781644903131-212","DOIUrl":"https://doi.org/10.21741/9781644903131-212","url":null,"abstract":"Abstract. The increasing demand for low surface roughness and long service life in highly loaded components, such as extruder shafts, requires high strength, functional reliability and long-term durability. Extruder shafts are applied in plastics technology and in the food industry for processing plastic melts, mixing and compounding. Screw and kneading elements are required for this purpose. The screw and kneading elements are pushed form-fittingly onto a splined shaft. The torque is transmitted by the splined shaft. [1] Main causes of wear and damage of extruder shafts are corrosion and mechanical load. High surface qualities, increased residual compressive stresses and increased surface hardness are possibilities to increase the durability of the splined shafts. These desired properties can be achieved by applying the ball burnishing technology. [2] By utilizing cold working processes, such as ball burnishing, it is possible to enhance the surface and subsurface properties to increase the lifespan of rotary components intended for transmitting high rotational torques. Due to the importance of considering the roughness of the initial surface, this study aimed to generate various roughness and surface profiles through the turning process to investigate their influence on the burnishing process results. For this purpose, shaft sections made of AISI H11 steel were pre-machined with different cutting inserts in order to set different surface roughnesses. Subsequently, a statistical experimental design was created by using the Taguchi method by varying feed rate, pressure and speed. As a main result, roughness and residual stresses on the surface were measured and compared with the initial conditions.","PeriodicalId":515987,"journal":{"name":"Materials Research Proceedings","volume":"67 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140973538","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 : 2024-05-15DOI: 10.21741/9781644903131-238
Denis Tretyakov
Abstract. The primary trend in modern metal forming can be characterised by the increase in the complexity of the technological processes and higher demand for the quality of the products. This naturally raises the requirements for the quality of modelling prediction of various aspects of metal forming process, such as tool wear, metal flow, fracture and defects formation, microstructure evolution and mechanical properties. However, various independent benchmarking studies [1] have shown that modelling predictions can be wrong even for well-calibrated models, and all the efforts with more detailed and metrologically better experiments didn’t lead to any significant leap in the prediction quality. As an attempt to implement some alternative approach, this paper investigates the applicability of an Artificial Intelligence (AI) approach, in particular Deep Learning models. The example of a recurrent neural network model predicting recrystallisation during hot forging of Inconel 718 is presented. The model considers the entire thermo-mechanical history at every point and is trained and blind-tested using actual experimental data.
{"title":"The prospects of implementation of artificial intelligence for modelling of microstructural parameters in metal forming processes","authors":"Denis Tretyakov","doi":"10.21741/9781644903131-238","DOIUrl":"https://doi.org/10.21741/9781644903131-238","url":null,"abstract":"Abstract. The primary trend in modern metal forming can be characterised by the increase in the complexity of the technological processes and higher demand for the quality of the products. This naturally raises the requirements for the quality of modelling prediction of various aspects of metal forming process, such as tool wear, metal flow, fracture and defects formation, microstructure evolution and mechanical properties. However, various independent benchmarking studies [1] have shown that modelling predictions can be wrong even for well-calibrated models, and all the efforts with more detailed and metrologically better experiments didn’t lead to any significant leap in the prediction quality. As an attempt to implement some alternative approach, this paper investigates the applicability of an Artificial Intelligence (AI) approach, in particular Deep Learning models. The example of a recurrent neural network model predicting recrystallisation during hot forging of Inconel 718 is presented. The model considers the entire thermo-mechanical history at every point and is trained and blind-tested using actual experimental data.","PeriodicalId":515987,"journal":{"name":"Materials Research Proceedings","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140973994","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 : 2024-05-15DOI: 10.21741/9781644903131-20
A. Viscusi
Abstract. Cold spray is a promising solution for the production of metallic coatings on polymer substrates. However, the adhesion mechanism between the impacting particle and the polymer in cold spraying depends on the chemical structure of the polymer itself. In this scenario, the emerging vitrimer polymers, which were proved to combine enhanced mechanical and chemical performances with abilities to be healed, welded, reprocessed, and recycled and that show a ductile behavior when exposed to given operating temperatures, can be particularly suitable for being functionalized by cold spray. Therefore, the aim of this work is to experimentally prove the feasibility of the metallization process via cold spray of epoxy vitrimer substrates. For this purpose, an epoxy vitrimer formulation was studied and experimentally characterized. Vitrimer-based panels were manufactured and used as substrates for the surface metallization. A low-pressure cold spray facility was used for the deposition of aluminum alloy particles. Microscope analyses were carried out for the characterization of the samples.
{"title":"Metallization of Vitrimers by cold spray: A preliminary study","authors":"A. Viscusi","doi":"10.21741/9781644903131-20","DOIUrl":"https://doi.org/10.21741/9781644903131-20","url":null,"abstract":"Abstract. Cold spray is a promising solution for the production of metallic coatings on polymer substrates. However, the adhesion mechanism between the impacting particle and the polymer in cold spraying depends on the chemical structure of the polymer itself. In this scenario, the emerging vitrimer polymers, which were proved to combine enhanced mechanical and chemical performances with abilities to be healed, welded, reprocessed, and recycled and that show a ductile behavior when exposed to given operating temperatures, can be particularly suitable for being functionalized by cold spray. Therefore, the aim of this work is to experimentally prove the feasibility of the metallization process via cold spray of epoxy vitrimer substrates. For this purpose, an epoxy vitrimer formulation was studied and experimentally characterized. Vitrimer-based panels were manufactured and used as substrates for the surface metallization. A low-pressure cold spray facility was used for the deposition of aluminum alloy particles. Microscope analyses were carried out for the characterization of the samples.","PeriodicalId":515987,"journal":{"name":"Materials Research Proceedings","volume":"24 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140975430","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 : 2024-05-15DOI: 10.21741/9781644903131-101
David Naumann
Abstract. Precise material characterization is a key factor not only for representative finite-element-analysis (FEA) in production technology, but also for product development in general. Hereby, the tensile test is of particular importance, as it can be used to determine the most relevant material parameters. These are used to ensure a better process and tool design but therefore material behavior has to be determined to a high level of precision [1]. Especially in the field of metal forming, strain rate sensitive material properties like work hardening, yield point or tensile strength need to be measured at constant strain rate to provide coherent data for material models in numerical forming simulations [2]. Current testing procedures control the strain rate with a feedback control, in which various measuring systems can be used. From this comes the necessity to investigate the influence of a strain rate controlled tensile testing procedure compared to a conventional crosshead-displacement controlled one. Thus, in the scope of this study, an optical strain rate controlled (OSRC) tensile test procedure with a digital image correlation (DIC) system, and a universal testing machine (UTM) was developed. The resulting mechanical properties and the evolution of the strain rate during the test of the steel DP600 (CR330Y590T-DH) and DC05 (CR4) were analyzed at a nominal strain rate of 0.4 %/s. In addition, the results obtained from displacement strain rate controlled (DSRC) tensile tests were compared. The results demonstrate that OSRC testing method enables the measurement of mechanical material properties at a higher level of precision in terms of constant strain rate compared to DSRC procedure.
{"title":"Influence of an optical strain rate controlled tensile testing method on mechanical properties of sheet metals","authors":"David Naumann","doi":"10.21741/9781644903131-101","DOIUrl":"https://doi.org/10.21741/9781644903131-101","url":null,"abstract":"Abstract. Precise material characterization is a key factor not only for representative finite-element-analysis (FEA) in production technology, but also for product development in general. Hereby, the tensile test is of particular importance, as it can be used to determine the most relevant material parameters. These are used to ensure a better process and tool design but therefore material behavior has to be determined to a high level of precision [1]. Especially in the field of metal forming, strain rate sensitive material properties like work hardening, yield point or tensile strength need to be measured at constant strain rate to provide coherent data for material models in numerical forming simulations [2]. Current testing procedures control the strain rate with a feedback control, in which various measuring systems can be used. From this comes the necessity to investigate the influence of a strain rate controlled tensile testing procedure compared to a conventional crosshead-displacement controlled one. Thus, in the scope of this study, an optical strain rate controlled (OSRC) tensile test procedure with a digital image correlation (DIC) system, and a universal testing machine (UTM) was developed. The resulting mechanical properties and the evolution of the strain rate during the test of the steel DP600 (CR330Y590T-DH) and DC05 (CR4) were analyzed at a nominal strain rate of 0.4 %/s. In addition, the results obtained from displacement strain rate controlled (DSRC) tensile tests were compared. The results demonstrate that OSRC testing method enables the measurement of mechanical material properties at a higher level of precision in terms of constant strain rate compared to DSRC procedure.","PeriodicalId":515987,"journal":{"name":"Materials Research Proceedings","volume":"15 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140976055","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 : 2024-05-15DOI: 10.21741/9781644903131-182
Núria Latorre
Abstract. Forming of aluminium-CFRP hybrid structures into complex shapes is key to decrease environmental impact in automotive industry. However, challenges such as preserving joint integrity after forming operations must be assessed. Therefore, the authors of this work have cold stamped hybrid aluminium-CFRP panels into omega shaped profiles with and without a mechanical interlocking joining technology. The effect of lubricant application, of the CFRP positioning (inside or outside the omega profile), and of the number of mechanical joints were studied. It was concluded that it is possible to cold stamp aluminium-CFRP prepreg panels even with mechanical joints into complex profiles when lubricant is used. Moreover, the position of the CFRP prepreg has a strong impact on the flange springback of the stamped part.
{"title":"Forming of mechanically interlocked aluminium and carbon fibre reinforced polymer parts with complex geometry","authors":"Núria Latorre","doi":"10.21741/9781644903131-182","DOIUrl":"https://doi.org/10.21741/9781644903131-182","url":null,"abstract":"Abstract. Forming of aluminium-CFRP hybrid structures into complex shapes is key to decrease environmental impact in automotive industry. However, challenges such as preserving joint integrity after forming operations must be assessed. Therefore, the authors of this work have cold stamped hybrid aluminium-CFRP panels into omega shaped profiles with and without a mechanical interlocking joining technology. The effect of lubricant application, of the CFRP positioning (inside or outside the omega profile), and of the number of mechanical joints were studied. It was concluded that it is possible to cold stamp aluminium-CFRP prepreg panels even with mechanical joints into complex profiles when lubricant is used. Moreover, the position of the CFRP prepreg has a strong impact on the flange springback of the stamped part.","PeriodicalId":515987,"journal":{"name":"Materials Research Proceedings","volume":"38 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140975801","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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