Pub Date : 2017-07-03DOI: 10.1080/20550340.2017.1348002
S. Saseendran, M. Wysocki, J. Varna
Abstract It is shown, using thermodynamically consistent linear viscoelastic material model that accounts for properties dependence on test temperature and cure state parameters, that for rheologically simple materials the cure and temperature related reduced times and shift factors are the same for all viscoelastic compliances, relaxation modulus, and Poisson’s ratio as well as for the storage and loss modulus. A necessary condition for that is that the cure and temperature parameters are affecting the reduced time only. This means that the Poisson’s ratio of polymeric materials, which for simplicity is often assumed constant, in fact exhibits a small dependence on time which is affected by temperature and state of cure. In this work, the evolution of the viscoelastic Poisson’s ratio of the commercial LY5052 epoxy resin is studied in relaxation test subjecting the specimen to constant axial strain. Specimens at several cure states are studied and Poisson’s ratio, defined as the lateral and axial strain ratio, is shown to evolve from 0.32 to 0.44 over time. Moreover, the data confirm that the cure state-dependent reduced time controlling the Poisson’s ratio development leads to the same shift functions as those identified in DMTA tests for storage modulus. The latter measurements also confirmed that the total shift can be considered as a sum of two shifts in the frequency domain, which means that function for reduced time calculation can be written as a product of two functions: one dependent on the test temperature and another one dependent on the cure state.
{"title":"Cure-state dependent viscoelastic Poisson’s ratio of LY5052 epoxy resin","authors":"S. Saseendran, M. Wysocki, J. Varna","doi":"10.1080/20550340.2017.1348002","DOIUrl":"https://doi.org/10.1080/20550340.2017.1348002","url":null,"abstract":"Abstract It is shown, using thermodynamically consistent linear viscoelastic material model that accounts for properties dependence on test temperature and cure state parameters, that for rheologically simple materials the cure and temperature related reduced times and shift factors are the same for all viscoelastic compliances, relaxation modulus, and Poisson’s ratio as well as for the storage and loss modulus. A necessary condition for that is that the cure and temperature parameters are affecting the reduced time only. This means that the Poisson’s ratio of polymeric materials, which for simplicity is often assumed constant, in fact exhibits a small dependence on time which is affected by temperature and state of cure. In this work, the evolution of the viscoelastic Poisson’s ratio of the commercial LY5052 epoxy resin is studied in relaxation test subjecting the specimen to constant axial strain. Specimens at several cure states are studied and Poisson’s ratio, defined as the lateral and axial strain ratio, is shown to evolve from 0.32 to 0.44 over time. Moreover, the data confirm that the cure state-dependent reduced time controlling the Poisson’s ratio development leads to the same shift functions as those identified in DMTA tests for storage modulus. The latter measurements also confirmed that the total shift can be considered as a sum of two shifts in the frequency domain, which means that function for reduced time calculation can be written as a product of two functions: one dependent on the test temperature and another one dependent on the cure state.","PeriodicalId":7243,"journal":{"name":"Advanced Manufacturing: Polymer & Composites Science","volume":"7 1","pages":"100 - 92"},"PeriodicalIF":0.0,"publicationDate":"2017-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81204421","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 : 2017-07-03DOI: 10.1080/20550340.2017.1355519
S. Hoa
Abstract 3D printing is the process where layers of materials are deposited to make structures of complex geometries. 4D printing is a process that combines 3D printing with the application of some activating agent in order to change the shape of the manufactured part after the process, e.g. the flat structure will change its shape to take up the desired complicated shape such as “curved” or “S” shaped. As such the 3D printing process does not have to spend time to print the intricate parts, and the process can be faster. The requirement for 4D printing is that materials with special characteristics that are responsive to an activating agent need to be used. 4D printing of composites utilizes the same concept of 4D printing, except that the materials used are long fiber composite materials. 4D printing of composites utilizes the shrinkage of the matrix resin, and the difference in coefficients of thermal contraction of layers with different fiber orientations to activate the change in shape upon curing and cooling. This behavior can be used to make parts with curved geometries without the need for a complex mold. As such manufacturing of pieces of curved shapes can be fast and economical. However, the degree of shape changing depends on the material properties, the fiber orientation, the lay up sequence and the manufacturing process. This paper presents the results obtained from a study on the effects of these aspects on the shape of the curved parts.
{"title":"Factors affecting the properties of composites made by 4D printing (moldless composites manufacturing)","authors":"S. Hoa","doi":"10.1080/20550340.2017.1355519","DOIUrl":"https://doi.org/10.1080/20550340.2017.1355519","url":null,"abstract":"Abstract 3D printing is the process where layers of materials are deposited to make structures of complex geometries. 4D printing is a process that combines 3D printing with the application of some activating agent in order to change the shape of the manufactured part after the process, e.g. the flat structure will change its shape to take up the desired complicated shape such as “curved” or “S” shaped. As such the 3D printing process does not have to spend time to print the intricate parts, and the process can be faster. The requirement for 4D printing is that materials with special characteristics that are responsive to an activating agent need to be used. 4D printing of composites utilizes the same concept of 4D printing, except that the materials used are long fiber composite materials. 4D printing of composites utilizes the shrinkage of the matrix resin, and the difference in coefficients of thermal contraction of layers with different fiber orientations to activate the change in shape upon curing and cooling. This behavior can be used to make parts with curved geometries without the need for a complex mold. As such manufacturing of pieces of curved shapes can be fast and economical. However, the degree of shape changing depends on the material properties, the fiber orientation, the lay up sequence and the manufacturing process. This paper presents the results obtained from a study on the effects of these aspects on the shape of the curved parts.","PeriodicalId":7243,"journal":{"name":"Advanced Manufacturing: Polymer & Composites Science","volume":"1 1","pages":"101 - 109"},"PeriodicalIF":0.0,"publicationDate":"2017-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89930468","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 : 2017-06-26DOI: 10.1080/20550340.2017.1341125
M. Ivey, Garrett W. Melenka, J. Carey, C. Ayranci
Abstract Material extrusion additive manufacturing (MEAM), a sub-branch of three-dimensional (3D) printing is growing in popularity. Test specimens were 3D-printed using commercial polylactic acid (PLA) filament, and PLA filament reinforced with short-carbon fibers (PLA/CF). As-printed specimens and specimens that were annealed at three different temperatures, then subjected to tensile testing. The internal microstructures of the samples were also examined. The effects of the short-carbon fiber fillers on the mechanical properties of 3D-printed PLA were investigated, and the effects of the annealing process on polymer crystallinity and mechanical properties. The annealing process was shown to increase the crystallinity of both sample groups, though no statistically significant effect of annealing on mechanical properties was observed. The tensile properties of the PLA and PLA/CF filaments showed that the addition of carbon fibers to the PLA filament led to a significant increase in elastic modulus of the MEAM samples.
{"title":"Characterizing short-fiber-reinforced composites produced using additive manufacturing","authors":"M. Ivey, Garrett W. Melenka, J. Carey, C. Ayranci","doi":"10.1080/20550340.2017.1341125","DOIUrl":"https://doi.org/10.1080/20550340.2017.1341125","url":null,"abstract":"Abstract Material extrusion additive manufacturing (MEAM), a sub-branch of three-dimensional (3D) printing is growing in popularity. Test specimens were 3D-printed using commercial polylactic acid (PLA) filament, and PLA filament reinforced with short-carbon fibers (PLA/CF). As-printed specimens and specimens that were annealed at three different temperatures, then subjected to tensile testing. The internal microstructures of the samples were also examined. The effects of the short-carbon fiber fillers on the mechanical properties of 3D-printed PLA were investigated, and the effects of the annealing process on polymer crystallinity and mechanical properties. The annealing process was shown to increase the crystallinity of both sample groups, though no statistically significant effect of annealing on mechanical properties was observed. The tensile properties of the PLA and PLA/CF filaments showed that the addition of carbon fibers to the PLA filament led to a significant increase in elastic modulus of the MEAM samples.","PeriodicalId":7243,"journal":{"name":"Advanced Manufacturing: Polymer & Composites Science","volume":"248 1","pages":"81 - 91"},"PeriodicalIF":0.0,"publicationDate":"2017-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78839828","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 : 2017-04-03DOI: 10.1080/20550340.2017.1319114
N. Samarth, P. Mahanwar
Abstract The free chlorine present in water which is used as a disinfectant is reported to reduce the life of the polymeric material. The objective of this work is to study the influence of chlorine concentration on low-density polyethylene (LDPE) and blends of LDPE with ethylene butene copolymer (EBC) and ethylene propylene diene terpolymer (EPDM). The LDPE blend with EBC and EPDM were tested with water containing 50, 500, and 5000 ppm chlorine under static condition for 500 h at 25 and 80 °C. It has been seen that at 5000 ppm chlorine concentration, the mechanical properties of LDPE, LDPE/EBC blend, and LDPE/EPDM blend changed drastically and a significant reduction in the elongation at break was found for LDPE, LDPE/EBC, and LDPE/EPDM blend. LDPE/EPDM shows stable modulus value for 5000 ppm as 80 °C. Chemical changes in the aged sample were studied by Fourier transform infrared spectroscopy (FTIR) where an increase in the O–H and C=O peaks were observed. The thermal characteristics of LDPE, LDPE/EBC blend, and LDPE/EPDM blends were investigated using DSC and TGA which shows that the melting temperature and crystalline melt temperature remains unchanged while percent crystallinity increases slightly. Scanning electron microscope showed that there was the formation of microcracks and cavities on the fracture surface of LDPE, LDPE/EBC blend, and LDPE/EPDM blend after exposure to a higher concentration of chlorine indicative of degradation. Furthermore, the Chlorine resistance of LDPE/EPDM blend at 5000 ppm chlorine concentration is much higher than that of pristine LDPE.
{"title":"Study and characterization of LDPE/Polyolefin elastomer and LDPE/EPDM blend: effect of chlorinated water on blend performance","authors":"N. Samarth, P. Mahanwar","doi":"10.1080/20550340.2017.1319114","DOIUrl":"https://doi.org/10.1080/20550340.2017.1319114","url":null,"abstract":"Abstract The free chlorine present in water which is used as a disinfectant is reported to reduce the life of the polymeric material. The objective of this work is to study the influence of chlorine concentration on low-density polyethylene (LDPE) and blends of LDPE with ethylene butene copolymer (EBC) and ethylene propylene diene terpolymer (EPDM). The LDPE blend with EBC and EPDM were tested with water containing 50, 500, and 5000 ppm chlorine under static condition for 500 h at 25 and 80 °C. It has been seen that at 5000 ppm chlorine concentration, the mechanical properties of LDPE, LDPE/EBC blend, and LDPE/EPDM blend changed drastically and a significant reduction in the elongation at break was found for LDPE, LDPE/EBC, and LDPE/EPDM blend. LDPE/EPDM shows stable modulus value for 5000 ppm as 80 °C. Chemical changes in the aged sample were studied by Fourier transform infrared spectroscopy (FTIR) where an increase in the O–H and C=O peaks were observed. The thermal characteristics of LDPE, LDPE/EBC blend, and LDPE/EPDM blends were investigated using DSC and TGA which shows that the melting temperature and crystalline melt temperature remains unchanged while percent crystallinity increases slightly. Scanning electron microscope showed that there was the formation of microcracks and cavities on the fracture surface of LDPE, LDPE/EBC blend, and LDPE/EPDM blend after exposure to a higher concentration of chlorine indicative of degradation. Furthermore, the Chlorine resistance of LDPE/EPDM blend at 5000 ppm chlorine concentration is much higher than that of pristine LDPE.","PeriodicalId":7243,"journal":{"name":"Advanced Manufacturing: Polymer & Composites Science","volume":"52 1","pages":"62 - 72"},"PeriodicalIF":0.0,"publicationDate":"2017-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75787416","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 : 2017-04-03DOI: 10.1080/20550340.2017.1317447
E. Oromiehie, B. Gangadhara Prusty, P. Compston, G. Rajan
Abstract There has been a tremendous growth of utilizing automated fiber placement (AFP) to manufacture highly precise components and large structures like fuselage panels and wing skins for high-end applications in aircrafts and next generation of spacecrafts. Consequently, in-situ identification of potential defects and strain level within the laminates is critical to ensure the quality and integrity of the final product. In this study, optical fiber Bragg grating sensors (FBGs) have been implemented as an on-line monitoring technique for simultaneous measurement of strain and temperature in AFP. In addition, it is also shown that, the embedded FBG sensors can remain within the laminate for continuous health monitoring after manufacturing process toward the identification of crack induced acoustic emissions.
{"title":"In-situ simultaneous measurement of strain and temperature in automated fiber placement (AFP) using optical fiber Bragg grating (FBG) sensors","authors":"E. Oromiehie, B. Gangadhara Prusty, P. Compston, G. Rajan","doi":"10.1080/20550340.2017.1317447","DOIUrl":"https://doi.org/10.1080/20550340.2017.1317447","url":null,"abstract":"Abstract There has been a tremendous growth of utilizing automated fiber placement (AFP) to manufacture highly precise components and large structures like fuselage panels and wing skins for high-end applications in aircrafts and next generation of spacecrafts. Consequently, in-situ identification of potential defects and strain level within the laminates is critical to ensure the quality and integrity of the final product. In this study, optical fiber Bragg grating sensors (FBGs) have been implemented as an on-line monitoring technique for simultaneous measurement of strain and temperature in AFP. In addition, it is also shown that, the embedded FBG sensors can remain within the laminate for continuous health monitoring after manufacturing process toward the identification of crack induced acoustic emissions.","PeriodicalId":7243,"journal":{"name":"Advanced Manufacturing: Polymer & Composites Science","volume":"8 1","pages":"52 - 61"},"PeriodicalIF":0.0,"publicationDate":"2017-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85260577","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 : 2017-04-03DOI: 10.1080/20550340.2017.1324351
M. Mat Salleh, K. Magniez, S. Pang, J. Dormanns, M. Staiger
Abstract Single-polymer composites based on cellulose I and/or II (aka all-cellulose composites) are emerging as a class of high-performance bio-based composite materials with mechanical properties suited to structural applications. There are various synthesis routes for the preparation of all-cellulose composites. However, little has been reported on the optimization of the processing variables affecting the properties of all-cellulose composites. In the present work, a range of all-cellulose composites were produced as single laminae via solvent infusion processing using a precursor of cellulose II fibers that were assembled as a woven 2D textile. The effects of dissolution time, dissolution temperature, and compaction pressure during hot pressing on the properties of the laminae were then systematically examined using a Taguchi design of experiment approach in order to identify the critical control factors. The tensile properties, fiber volume fraction, and crystallinity of the laminae were determined. Statistical analysis of variance and the signal-to-noise ratio were used to rank the importance of key control factors.
{"title":"Parametric optimization of the processing of all-cellulose composite laminae","authors":"M. Mat Salleh, K. Magniez, S. Pang, J. Dormanns, M. Staiger","doi":"10.1080/20550340.2017.1324351","DOIUrl":"https://doi.org/10.1080/20550340.2017.1324351","url":null,"abstract":"Abstract Single-polymer composites based on cellulose I and/or II (aka all-cellulose composites) are emerging as a class of high-performance bio-based composite materials with mechanical properties suited to structural applications. There are various synthesis routes for the preparation of all-cellulose composites. However, little has been reported on the optimization of the processing variables affecting the properties of all-cellulose composites. In the present work, a range of all-cellulose composites were produced as single laminae via solvent infusion processing using a precursor of cellulose II fibers that were assembled as a woven 2D textile. The effects of dissolution time, dissolution temperature, and compaction pressure during hot pressing on the properties of the laminae were then systematically examined using a Taguchi design of experiment approach in order to identify the critical control factors. The tensile properties, fiber volume fraction, and crystallinity of the laminae were determined. Statistical analysis of variance and the signal-to-noise ratio were used to rank the importance of key control factors.","PeriodicalId":7243,"journal":{"name":"Advanced Manufacturing: Polymer & Composites Science","volume":"128 1","pages":"73 - 79"},"PeriodicalIF":0.0,"publicationDate":"2017-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87938368","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 : 2017-04-03DOI: 10.1080/20550340.2017.1315908
A. Yong, G. Sims, S. Gnaniah, S. Ogin, P. Smith
Abstract Three measurement techniques used to measure the glass transition temperature (Tg) have been subjected to a critical comparison; dynamic mechanical analysis (DMA), thermomechanical analysis, and differential scanning calorimetry. A new procedure, whereby different specimens are tested over a range of heating rates, has been used in order to eliminate the effects of thermal lag and determine a Tg independent of heating rate (Tg(0)). It has been shown that for measurements of Tg(0) for composites, the DMA thermal lag “corrected” method gave the most reliable data. The work has provided additional guidance on these techniques that could usefully be incorporated in future standards, to improve precision, comparisons, and consistency of Tg measurement.
{"title":"Heating rate effects on thermal analysis measurement of Tg in composite materials","authors":"A. Yong, G. Sims, S. Gnaniah, S. Ogin, P. Smith","doi":"10.1080/20550340.2017.1315908","DOIUrl":"https://doi.org/10.1080/20550340.2017.1315908","url":null,"abstract":"Abstract Three measurement techniques used to measure the glass transition temperature (Tg) have been subjected to a critical comparison; dynamic mechanical analysis (DMA), thermomechanical analysis, and differential scanning calorimetry. A new procedure, whereby different specimens are tested over a range of heating rates, has been used in order to eliminate the effects of thermal lag and determine a Tg independent of heating rate (Tg(0)). It has been shown that for measurements of Tg(0) for composites, the DMA thermal lag “corrected” method gave the most reliable data. The work has provided additional guidance on these techniques that could usefully be incorporated in future standards, to improve precision, comparisons, and consistency of Tg measurement.","PeriodicalId":7243,"journal":{"name":"Advanced Manufacturing: Polymer & Composites Science","volume":"23 1","pages":"43 - 51"},"PeriodicalIF":0.0,"publicationDate":"2017-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74306393","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 : 2017-01-02DOI: 10.1080/20550340.2017.1283100
Frederic J. C. Fischer, Matthias Beyrle, Arthur-Hans Thellmann, Manuel Endrass, Thomas Stefani, T. Gerngross, M. Kupke
Abstract Carbon fiber-reinforced thermoplastics offer the possibility for short lead times and dustless assembly in aerospace applications. However, their great potential for efficient processing to date is not entirely exploited. At the Center for Lightweight Production Technology (ZLP) in Augsburg smart automation of thermoplastic composite production is investigated. To assess the overall process chain a sine wave beam designed as crash-absorber serves as demonstrator. The production process from as-delivered material to final assembly is presented. In addition to non-destructive testing at the end of the value adding process chain, production-integration quality assurance, and process characterization serve to evaluate each process step. In this context, water-coupled ultrasonic testing as an established method in aerospace production is used to assess the degree of consolidation after vacuum consolidation and press-forming. Thus, quality issues and crucial process parameters can be identified and optimized to improve robustness.
{"title":"Corrugated composites: production-integrated quality assurance in carbon fiber reinforced thermoplastic sine wave beam production","authors":"Frederic J. C. Fischer, Matthias Beyrle, Arthur-Hans Thellmann, Manuel Endrass, Thomas Stefani, T. Gerngross, M. Kupke","doi":"10.1080/20550340.2017.1283100","DOIUrl":"https://doi.org/10.1080/20550340.2017.1283100","url":null,"abstract":"Abstract Carbon fiber-reinforced thermoplastics offer the possibility for short lead times and dustless assembly in aerospace applications. However, their great potential for efficient processing to date is not entirely exploited. At the Center for Lightweight Production Technology (ZLP) in Augsburg smart automation of thermoplastic composite production is investigated. To assess the overall process chain a sine wave beam designed as crash-absorber serves as demonstrator. The production process from as-delivered material to final assembly is presented. In addition to non-destructive testing at the end of the value adding process chain, production-integration quality assurance, and process characterization serve to evaluate each process step. In this context, water-coupled ultrasonic testing as an established method in aerospace production is used to assess the degree of consolidation after vacuum consolidation and press-forming. Thus, quality issues and crucial process parameters can be identified and optimized to improve robustness.","PeriodicalId":7243,"journal":{"name":"Advanced Manufacturing: Polymer & Composites Science","volume":"95 3 1","pages":"10 - 20"},"PeriodicalIF":0.0,"publicationDate":"2017-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83343486","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 : 2017-01-02DOI: 10.1080/20550340.2017.1291398
Marko Szcesny, F. Heieck, S. Carosella, P. Middendorf, H. Sehrschön, M. Schneiderbauer
Abstract Breaking down the cost structure of state-of-the-art CFRP part shows that a major share of the costs is caused by labor and equipment as well as process energy consumption. Therefore, the main goal of the EU funded FP7 project LOWFLIP (Low Cost Flexible Integrated Composite Process) has been the reduction of these costs by introducing new technologies into CFRP production processes. The LOWFLIP concept focuses on three main aspects:• Development of a new out-of-autoclave (OOA) prepreg system with snap cure capabilities.• Development of a direct 3D placement technology for plies and tapes.• Development of energy efficient and fast heating toolings. The main content of this paper is detailed information on a novel direct 3D prepreg layup process for automated production of large-scale fiber reinforced parts of small and medium lot sizes. The advanced ply placement process, which is able to drape and compact unidirectional prepreg tapes with currently up to 300 mm ply width directly into a double curved tooling, is being introduced. Two large-scale demonstrator parts from the transport and aerospace sector will be presented. Experiences gained during prototype manufacturing will be reflected and benchmarks of the equipment are presented.
{"title":"The advanced ply placement process – an innovative direct 3D placement technology for plies and tapes","authors":"Marko Szcesny, F. Heieck, S. Carosella, P. Middendorf, H. Sehrschön, M. Schneiderbauer","doi":"10.1080/20550340.2017.1291398","DOIUrl":"https://doi.org/10.1080/20550340.2017.1291398","url":null,"abstract":"Abstract Breaking down the cost structure of state-of-the-art CFRP part shows that a major share of the costs is caused by labor and equipment as well as process energy consumption. Therefore, the main goal of the EU funded FP7 project LOWFLIP (Low Cost Flexible Integrated Composite Process) has been the reduction of these costs by introducing new technologies into CFRP production processes. The LOWFLIP concept focuses on three main aspects:• Development of a new out-of-autoclave (OOA) prepreg system with snap cure capabilities.• Development of a direct 3D placement technology for plies and tapes.• Development of energy efficient and fast heating toolings. The main content of this paper is detailed information on a novel direct 3D prepreg layup process for automated production of large-scale fiber reinforced parts of small and medium lot sizes. The advanced ply placement process, which is able to drape and compact unidirectional prepreg tapes with currently up to 300 mm ply width directly into a double curved tooling, is being introduced. Two large-scale demonstrator parts from the transport and aerospace sector will be presented. Experiences gained during prototype manufacturing will be reflected and benchmarks of the equipment are presented.","PeriodicalId":7243,"journal":{"name":"Advanced Manufacturing: Polymer & Composites Science","volume":"42 1","pages":"2 - 9"},"PeriodicalIF":0.0,"publicationDate":"2017-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75724135","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 : 2017-01-02DOI: 10.1080/20550340.2017.1311094
Imad Zammar, M. Huq, I. Mantegh, A. Yousefpour, M. Ahmadi
Abstract The resistance welding technique for thermoplastic composites (TPCs) entails melting the TPC polymer at the joint interface using heat generated by resistive (Joule) heating of a conductive mesh or heating element placed between the surfaces to be welded. The continuous resistance welding (CRW) is an automated large-scale resistance welding technique that consists of a moving voltage source along the heating element creating a continuous weld along its path. This paper presents a transient model that is developed to predict the heat transfer in TPCs in all three dimensions during the CRW process. The model is finite element in nature and includes both the resistive and thermal conductivity behaviors of the material involved. The significance of this modeling approach is that it captures the movement of the electrical connection, as well as the nonuniform distribution of the current and resistive heating along the length and width of the weld seam. The modeling results are compared with experimental data obtained by thermocouples and an infrared camera, and exhibit solid conformance for predicting the trend of variations in weld temperature.
{"title":"A three-dimensional transient model for heat transfer in thermoplastic composites during continuous resistance welding","authors":"Imad Zammar, M. Huq, I. Mantegh, A. Yousefpour, M. Ahmadi","doi":"10.1080/20550340.2017.1311094","DOIUrl":"https://doi.org/10.1080/20550340.2017.1311094","url":null,"abstract":"Abstract The resistance welding technique for thermoplastic composites (TPCs) entails melting the TPC polymer at the joint interface using heat generated by resistive (Joule) heating of a conductive mesh or heating element placed between the surfaces to be welded. The continuous resistance welding (CRW) is an automated large-scale resistance welding technique that consists of a moving voltage source along the heating element creating a continuous weld along its path. This paper presents a transient model that is developed to predict the heat transfer in TPCs in all three dimensions during the CRW process. The model is finite element in nature and includes both the resistive and thermal conductivity behaviors of the material involved. The significance of this modeling approach is that it captures the movement of the electrical connection, as well as the nonuniform distribution of the current and resistive heating along the length and width of the weld seam. The modeling results are compared with experimental data obtained by thermocouples and an infrared camera, and exhibit solid conformance for predicting the trend of variations in weld temperature.","PeriodicalId":7243,"journal":{"name":"Advanced Manufacturing: Polymer & Composites Science","volume":"47 1","pages":"32 - 41"},"PeriodicalIF":0.0,"publicationDate":"2017-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90885124","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：