Pub Date : 2024-03-25DOI: 10.1177/00219983241241304
Milad Abbasi, Abolfazl Khalkhali, Johannes Sackmann
Developing a reliable and robust finite element model of a carbon fiber-reinforced plastic (CFRP) composite structure is investigated by using the LS-DYNA solver and Python. This study tries to provide a systematic numerical approach to cover the principal impediment to adaptation of composite energy absorbers, that is the lack of a reliable predictive method. The proposed procedure aims to further the understanding of advanced composite structures’ behavior during the crash phenomenon by developing an accurate finite element model. To do so, the mechanical properties of the material were extracted from American Society for Testing and Materials (ASTM) standard test methods, followed by experimental investigation of circular CFRP tubes undergoing quasi-static loading. A numerical simulation framework was then utilized to scrutinize the effectiveness of simulation parameters on the crushing mechanism. Finally, a systematic approach based on machine learning techniques was performed to adjust non-physical modeling parameters for further calibration and validation. In this regard, a versatile Python code was developed to automate pre-processing, processing, and post-processing steps. The code also provides a groundwork to perform machine learning techniques. Interestingly, the numerical and experimental results were highly correlated with a correlation coefficient of almost 90%. Additionally, several non-physical numerical parameters were found to be inactive, while some else were identified as effective parameters, and their corresponding effectiveness was quantitatively extracted and discussed for the first time in the literature.
{"title":"A novel systematic approach for robust numerical simulation of carbon fiber-reinforced plastic circular tubes: Utilizing machine-learning techniques for calibration and validation","authors":"Milad Abbasi, Abolfazl Khalkhali, Johannes Sackmann","doi":"10.1177/00219983241241304","DOIUrl":"https://doi.org/10.1177/00219983241241304","url":null,"abstract":"Developing a reliable and robust finite element model of a carbon fiber-reinforced plastic (CFRP) composite structure is investigated by using the LS-DYNA solver and Python. This study tries to provide a systematic numerical approach to cover the principal impediment to adaptation of composite energy absorbers, that is the lack of a reliable predictive method. The proposed procedure aims to further the understanding of advanced composite structures’ behavior during the crash phenomenon by developing an accurate finite element model. To do so, the mechanical properties of the material were extracted from American Society for Testing and Materials (ASTM) standard test methods, followed by experimental investigation of circular CFRP tubes undergoing quasi-static loading. A numerical simulation framework was then utilized to scrutinize the effectiveness of simulation parameters on the crushing mechanism. Finally, a systematic approach based on machine learning techniques was performed to adjust non-physical modeling parameters for further calibration and validation. In this regard, a versatile Python code was developed to automate pre-processing, processing, and post-processing steps. The code also provides a groundwork to perform machine learning techniques. Interestingly, the numerical and experimental results were highly correlated with a correlation coefficient of almost 90%. Additionally, several non-physical numerical parameters were found to be inactive, while some else were identified as effective parameters, and their corresponding effectiveness was quantitatively extracted and discussed for the first time in the literature.","PeriodicalId":15489,"journal":{"name":"Journal of Composite Materials","volume":"260 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140301313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-25DOI: 10.1177/00219983241241771
László Kovács, Gábor Romhány
In this paper, a novel methodology is presented to evaluate the true nonlinear shear response of continuous fiber-reinforced plastic (CFRP) unidirectional laminae. It requires simple off-axis tensile experiments to be conducted and a finite element (FE) representation of them with a material constitutive law capable of handling nonlinearity in shear. Upon successful evaluation of the normal stiffness properties, the shear stress-strain response is derived via numerical calibration of the underlying FE models. The presented approach is also demonstrated by processing the raw data of an extensive material characterization test campaign conducted on a thermoplastic matrix CFRP. The outcome is compared to the conventional methods for shear response derivation using relevant standards such as ASTM D3518 and ASTM D5379. It has been successfully demonstrated that the pseudo-hardening phenomenon obtained from standard shear experiments as a result of fibers aligning with load direction can be eliminated with off-axis specimen tension experiments, thus, the true shear stress versus deformation response can be extracted up to failure. The main purpose of current work is to demonstrate the inconsistency in the available standard methods related to mechanical testing-based derivation of nonlinear in-plane shear behavior of UD plies. In addition, a novel technique is presented to achieve a more accurate prediction of nonlinear shear stress and strain along the entire representative loading range that contributes to more accurate simulations of composite parts up to failure and thus, better strength predictions.
{"title":"Numerically assisted calibration procedure of nonlinear in-plane shear properties of unidirectional composite laminae based on off-axis tensile experiments","authors":"László Kovács, Gábor Romhány","doi":"10.1177/00219983241241771","DOIUrl":"https://doi.org/10.1177/00219983241241771","url":null,"abstract":"In this paper, a novel methodology is presented to evaluate the true nonlinear shear response of continuous fiber-reinforced plastic (CFRP) unidirectional laminae. It requires simple off-axis tensile experiments to be conducted and a finite element (FE) representation of them with a material constitutive law capable of handling nonlinearity in shear. Upon successful evaluation of the normal stiffness properties, the shear stress-strain response is derived via numerical calibration of the underlying FE models. The presented approach is also demonstrated by processing the raw data of an extensive material characterization test campaign conducted on a thermoplastic matrix CFRP. The outcome is compared to the conventional methods for shear response derivation using relevant standards such as ASTM D3518 and ASTM D5379. It has been successfully demonstrated that the pseudo-hardening phenomenon obtained from standard shear experiments as a result of fibers aligning with load direction can be eliminated with off-axis specimen tension experiments, thus, the true shear stress versus deformation response can be extracted up to failure. The main purpose of current work is to demonstrate the inconsistency in the available standard methods related to mechanical testing-based derivation of nonlinear in-plane shear behavior of UD plies. In addition, a novel technique is presented to achieve a more accurate prediction of nonlinear shear stress and strain along the entire representative loading range that contributes to more accurate simulations of composite parts up to failure and thus, better strength predictions.","PeriodicalId":15489,"journal":{"name":"Journal of Composite Materials","volume":"72 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140303173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-23DOI: 10.1177/00219983241242453
Mohanad Idrees, Giuseppe R. Palmese, Nicolas J. Alvarez
Interleaving is a well-recognized method for enhancing the interlaminar fracture toughness of composite materials. However, theoretical toughness is often not realized since cracks tend to propagate through regions of lower toughness. While most studies have focused on the effect of interleaf properties, e.g., thickness and interleaf resin properties, on composite interlaminar fracture toughness, the effect of matrix resin properties on interleaved composite toughness has been overlooked. Recently, we hypothesized that there is a relationship between toughness translation and the ratio of matrix to interleaf resin toughness. In this work, we use additive manufacturing to test this hypothesis with a range of resins in interleaved composite. Toughness is quantified via mode I delamination resistance. Our results confirm our hypothesis that the ratio of matrix to interleaf resin fracture toughness, i.e., the ratio of [Formula: see text], is directly correlated to the degree of toughness translation. More specifically, a ratio of approximately 0.5 is required for effective interleaving; below 0.5, the toughness translation is significantly below the theoretical value. This approach has important implications for the design and fabrication of tough composites via choice of resins.
交错是一种公认的提高复合材料层间断裂韧性的方法。然而，由于裂纹往往会通过韧性较低的区域传播，因此理论上的韧性往往无法实现。大多数研究都集中在层间特性（如厚度和层间树脂特性）对复合材料层间断裂韧性的影响上，而基体树脂特性对交错复合材料韧性的影响却被忽视了。最近，我们假设韧性平移与基体和层间树脂韧性的比例之间存在关系。在这项工作中，我们利用快速成型技术，对交错复合材料中的一系列树脂进行了测试。韧性通过模式 I 分层阻力进行量化。我们的结果证实了我们的假设，即基体与夹层树脂断裂韧性之比（即[公式：见正文]之比）与韧性平移程度直接相关。更具体地说，有效交错所需的比率约为 0.5；低于 0.5 时，韧性平移将大大低于理论值。这种方法对于通过选择树脂来设计和制造韧性复合材料具有重要意义。
{"title":"The effect of resin properties on toughness translation in interleaved composites","authors":"Mohanad Idrees, Giuseppe R. Palmese, Nicolas J. Alvarez","doi":"10.1177/00219983241242453","DOIUrl":"https://doi.org/10.1177/00219983241242453","url":null,"abstract":"Interleaving is a well-recognized method for enhancing the interlaminar fracture toughness of composite materials. However, theoretical toughness is often not realized since cracks tend to propagate through regions of lower toughness. While most studies have focused on the effect of interleaf properties, e.g., thickness and interleaf resin properties, on composite interlaminar fracture toughness, the effect of matrix resin properties on interleaved composite toughness has been overlooked. Recently, we hypothesized that there is a relationship between toughness translation and the ratio of matrix to interleaf resin toughness. In this work, we use additive manufacturing to test this hypothesis with a range of resins in interleaved composite. Toughness is quantified via mode I delamination resistance. Our results confirm our hypothesis that the ratio of matrix to interleaf resin fracture toughness, i.e., the ratio of [Formula: see text], is directly correlated to the degree of toughness translation. More specifically, a ratio of approximately 0.5 is required for effective interleaving; below 0.5, the toughness translation is significantly below the theoretical value. This approach has important implications for the design and fabrication of tough composites via choice of resins.","PeriodicalId":15489,"journal":{"name":"Journal of Composite Materials","volume":"23 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140199917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-22DOI: 10.1177/00219983241238652
Sven Hellmann, Thomas Gereke, Wolfgang Truemper, Chokri Cherif
This study focuses on the development of an advanced high heating rate thermobonding process for the manufacture of preforms and the metrological characterisation of the process. The process involves passing hot air, driven by pressure differential, through a textile stack consisting of several plies of a quadraxial fabric coated with a binder. Heat is transferred into the stack and into the binder by forced convection, melting the binder. The process is used in the same way to cool the stack and binder so that the plies are bonded together. The pressure differential compacts the stack. The comprehensive methodological characterisation of the process includes first determining the air permeability of the stack and thus the volume flow of air as a function of the number of plies stacked. Further characterisation focuses on a comprehensive determination of the heating behaviour in the individual plies as a function of time, using thermocouples and thermal imaging to determine the temperatures of hot air and textiles. These are compared and related using a mathematical approach as different values have been found. The results indicate high heating rates, reducing process time by at least 85% compared to previous binder activation methods. In addition, the cantilever method assesses the flexural stiffness of the processed stacks and shows a twofold improvement in bond strength compared to uncompacted stacks. Results and discussions include orifice based volume flow determination, thermography calibration, mathematical modelling, stiffness of bonded textile plies, process comparison, process control and potential energy savings.
{"title":"Development and characterization of a through-air thermobonding process with high heating rate for activating the binder and producing preforms for fibre-reinforced polymers","authors":"Sven Hellmann, Thomas Gereke, Wolfgang Truemper, Chokri Cherif","doi":"10.1177/00219983241238652","DOIUrl":"https://doi.org/10.1177/00219983241238652","url":null,"abstract":"This study focuses on the development of an advanced high heating rate thermobonding process for the manufacture of preforms and the metrological characterisation of the process. The process involves passing hot air, driven by pressure differential, through a textile stack consisting of several plies of a quadraxial fabric coated with a binder. Heat is transferred into the stack and into the binder by forced convection, melting the binder. The process is used in the same way to cool the stack and binder so that the plies are bonded together. The pressure differential compacts the stack. The comprehensive methodological characterisation of the process includes first determining the air permeability of the stack and thus the volume flow of air as a function of the number of plies stacked. Further characterisation focuses on a comprehensive determination of the heating behaviour in the individual plies as a function of time, using thermocouples and thermal imaging to determine the temperatures of hot air and textiles. These are compared and related using a mathematical approach as different values have been found. The results indicate high heating rates, reducing process time by at least 85% compared to previous binder activation methods. In addition, the cantilever method assesses the flexural stiffness of the processed stacks and shows a twofold improvement in bond strength compared to uncompacted stacks. Results and discussions include orifice based volume flow determination, thermography calibration, mathematical modelling, stiffness of bonded textile plies, process comparison, process control and potential energy savings.","PeriodicalId":15489,"journal":{"name":"Journal of Composite Materials","volume":"22 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140199964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-20DOI: 10.1177/00219983241242898
Björn Maack
Remotely in-line monitored acoustic emission (AE) of interlaminar shear strength tests in a 3-point bending test of fiber-reinforced polymer composites (FRP) conducted under cryogenic conditions in liquid nitrogen (LN2) were studied. The AE sensors were reversibly mounted at the outer components of the testing machine to thermally decouple them from the cryogenic area and use AE signal transmission through the testing machine structure as a waveguide. The damage mechanisms and effect of the cryogenic temperature were studied at 296 K room temperature (RT) and in LN2 at 77 K, considering machine and process noises. The correlation of machine data with acoustics and the AE hit analysis revealed matrix cracking as the most frequent damage mechanism under both conditions but with different failure mechanisms. At RT and applying higher loads, the most damage suddenly occurred, and the specimen failed. In LN2, the damage occurred continuously from the beginning of testing. The amount of fiber failure increased, and the AE feature ranges enlarged. This study presents a method by AE for remote monitoring the mechanical response of FRP in cryogenic fluids such as liquid hydrogen. The method provides a new approach to support the more efficient development of FRP materials for storage vessel structures and structural health monitoring systems.
{"title":"In-line monitoring of cryogenic three-point bending test of fiber-reinforced composites using acoustic emission","authors":"Björn Maack","doi":"10.1177/00219983241242898","DOIUrl":"https://doi.org/10.1177/00219983241242898","url":null,"abstract":"Remotely in-line monitored acoustic emission (AE) of interlaminar shear strength tests in a 3-point bending test of fiber-reinforced polymer composites (FRP) conducted under cryogenic conditions in liquid nitrogen (LN2) were studied. The AE sensors were reversibly mounted at the outer components of the testing machine to thermally decouple them from the cryogenic area and use AE signal transmission through the testing machine structure as a waveguide. The damage mechanisms and effect of the cryogenic temperature were studied at 296 K room temperature (RT) and in LN2 at 77 K, considering machine and process noises. The correlation of machine data with acoustics and the AE hit analysis revealed matrix cracking as the most frequent damage mechanism under both conditions but with different failure mechanisms. At RT and applying higher loads, the most damage suddenly occurred, and the specimen failed. In LN2, the damage occurred continuously from the beginning of testing. The amount of fiber failure increased, and the AE feature ranges enlarged. This study presents a method by AE for remote monitoring the mechanical response of FRP in cryogenic fluids such as liquid hydrogen. The method provides a new approach to support the more efficient development of FRP materials for storage vessel structures and structural health monitoring systems.","PeriodicalId":15489,"journal":{"name":"Journal of Composite Materials","volume":"309 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140199957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-16DOI: 10.1177/00219983241240819
Khalissa Saada, Chouki Farsi, Salah Amroune, Mohamed Fnides, Moussa Zaoui, Hocine Heraiz
This study explores the relationship between natural fiber filling density (10%, 15%, 25%) and its impact on the bending properties of polymer compounds reinforced with Diss, Sisal and Luffa fibers. Using advanced techniques like fiber analysis and Fourier transform infrared spectrometry (FTIR), the research reveals that a 25% filling density results in the highest stress values (25.61 MPa, 22.21 MPa and 20.88 MPa) for Diss, Sisal and Luffa compounds, respectively, fostering robust bonds in Diss-reinforced polymers. The Artificial Neural Network (ANN) model demonstrates superior predictive capability with correlation coefficients exceeding 0.99 for stress and displacement, outperforming Response Surface Methodology (RSM). Analysis of Variance (ANOVA) underscores the impact of sample section parameters and fiber rate on stress, establishing the significance of type parameters and fiber rate on displacement. This integration of ANN and RSM represents a paradigm shift in predicting bending mechanical properties, advancing our understanding of composite materials for innovative applications.
{"title":"Examining the bending test properties of bio-composites strengthened with fibers through a combination of experimental and modeling approaches","authors":"Khalissa Saada, Chouki Farsi, Salah Amroune, Mohamed Fnides, Moussa Zaoui, Hocine Heraiz","doi":"10.1177/00219983241240819","DOIUrl":"https://doi.org/10.1177/00219983241240819","url":null,"abstract":"This study explores the relationship between natural fiber filling density (10%, 15%, 25%) and its impact on the bending properties of polymer compounds reinforced with Diss, Sisal and Luffa fibers. Using advanced techniques like fiber analysis and Fourier transform infrared spectrometry (FTIR), the research reveals that a 25% filling density results in the highest stress values (25.61 MPa, 22.21 MPa and 20.88 MPa) for Diss, Sisal and Luffa compounds, respectively, fostering robust bonds in Diss-reinforced polymers. The Artificial Neural Network (ANN) model demonstrates superior predictive capability with correlation coefficients exceeding 0.99 for stress and displacement, outperforming Response Surface Methodology (RSM). Analysis of Variance (ANOVA) underscores the impact of sample section parameters and fiber rate on stress, establishing the significance of type parameters and fiber rate on displacement. This integration of ANN and RSM represents a paradigm shift in predicting bending mechanical properties, advancing our understanding of composite materials for innovative applications.","PeriodicalId":15489,"journal":{"name":"Journal of Composite Materials","volume":"16 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140153355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An attempt was made to map the distribution of stress in fibrous composites with imperfect bonding. Two analytical micro-mechanics models were developed. In the first model, the composite was subjected to axial tensile loading, parallel to the fiber direction, and the assumption of iso-strain was employed to derive the control equations. In the second model, the composite was loaded in the direction transverse to the fiber. An iso-stress condition was employed, and Airy stress function was utilized to articulate the stress and displacement equations. An assumption of how the stress is transferred between the matrix and the fiber was introduced in both models. To investigate and validate the models, specimens were fabricated using a carbon plain weave fabric and a geopolymer matrix. Single fiber pullout and three-point bending tests were carried out. The maximum average tensile stress obtained from the three-point bending tests, as well as the mechanical properties of the fiber and geopolymer, served as input for the models. Results indicate that the effect of the level of bonding is very high in the transverse direction while almost negligible in the axial direction. The difference in the maximum value of the axial tensile stress at the fiber-matrix interface was used to calculate the numerical value of the interfacial shear strength, and the numerical result matched the data obtained from the single fiber pullout test.
{"title":"The effect of imperfect bonding on stress distribution in fibrous composites","authors":"Parvaneh Kheirkhah Barzoki, Tianyi Hua, Ouli Fu, Yasser Gowayed","doi":"10.1177/00219983241241497","DOIUrl":"https://doi.org/10.1177/00219983241241497","url":null,"abstract":"An attempt was made to map the distribution of stress in fibrous composites with imperfect bonding. Two analytical micro-mechanics models were developed. In the first model, the composite was subjected to axial tensile loading, parallel to the fiber direction, and the assumption of iso-strain was employed to derive the control equations. In the second model, the composite was loaded in the direction transverse to the fiber. An iso-stress condition was employed, and Airy stress function was utilized to articulate the stress and displacement equations. An assumption of how the stress is transferred between the matrix and the fiber was introduced in both models. To investigate and validate the models, specimens were fabricated using a carbon plain weave fabric and a geopolymer matrix. Single fiber pullout and three-point bending tests were carried out. The maximum average tensile stress obtained from the three-point bending tests, as well as the mechanical properties of the fiber and geopolymer, served as input for the models. Results indicate that the effect of the level of bonding is very high in the transverse direction while almost negligible in the axial direction. The difference in the maximum value of the axial tensile stress at the fiber-matrix interface was used to calculate the numerical value of the interfacial shear strength, and the numerical result matched the data obtained from the single fiber pullout test.","PeriodicalId":15489,"journal":{"name":"Journal of Composite Materials","volume":"5 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140153285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-13DOI: 10.1177/00219983241241119
Meng Han, Zhichao Wang, Xingyu Zhang, Yang Ni, Weixin Ma, Ge Qi, Xiujing Han, Vadim V. Silberschmidt, Chuwei Zhou
Needle-punched carbon/carbon (NP C/C) composite is widely used in rocket-engine nozzles and re-entry vehicles. Recyclable technology expedited the research on repeated oxidation and residual mechaincal properties of thermal-protection materials. In this study, the critical longitudinal compression strengths before and after oxidation are derived based on the Timoshenko beam theory. Three repetitions of short-term oxidation cycles and compression experiments are investigated. The average oxidation rate of this composite was 5∼6% in 10 min and kept linear increase. In-plane and out-of-plane compressive strengths of NP C/C composite diminish quasi-linearly due to oxidation at 1000°C, with their moduli decreasing in a periodically slow-sharp pattern. After three oxidation cycles, the levels of residual in-plane modulus and strength were 55.20% and 56.89%, respectively, while the resudual out-of-plane modulus and strength were 44.65% and 47.23%, respectively. The results showed that the material exhibited the pesudo-plastical behaviour after oxidation, cracks grew along the punched conical structures formed by the punching technology. In-plane and out-of-plane modulus were more sensitive than their strengths after first oxidation cycle.
{"title":"Short-term oxidation and residual compression properties of needle-punched carbon/carbon composites","authors":"Meng Han, Zhichao Wang, Xingyu Zhang, Yang Ni, Weixin Ma, Ge Qi, Xiujing Han, Vadim V. Silberschmidt, Chuwei Zhou","doi":"10.1177/00219983241241119","DOIUrl":"https://doi.org/10.1177/00219983241241119","url":null,"abstract":"Needle-punched carbon/carbon (NP C/C) composite is widely used in rocket-engine nozzles and re-entry vehicles. Recyclable technology expedited the research on repeated oxidation and residual mechaincal properties of thermal-protection materials. In this study, the critical longitudinal compression strengths before and after oxidation are derived based on the Timoshenko beam theory. Three repetitions of short-term oxidation cycles and compression experiments are investigated. The average oxidation rate of this composite was 5∼6% in 10 min and kept linear increase. In-plane and out-of-plane compressive strengths of NP C/C composite diminish quasi-linearly due to oxidation at 1000°C, with their moduli decreasing in a periodically slow-sharp pattern. After three oxidation cycles, the levels of residual in-plane modulus and strength were 55.20% and 56.89%, respectively, while the resudual out-of-plane modulus and strength were 44.65% and 47.23%, respectively. The results showed that the material exhibited the pesudo-plastical behaviour after oxidation, cracks grew along the punched conical structures formed by the punching technology. In-plane and out-of-plane modulus were more sensitive than their strengths after first oxidation cycle.","PeriodicalId":15489,"journal":{"name":"Journal of Composite Materials","volume":"35 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140127811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thermoplastic carbon fiber-reinforced plastics (CFRPs) are increasingly utilized in the aerospace industry owing to their beneficial properties and enhanced formability relative to thermoset CFRPs. Despite the extensive use of these materials, studies focusing on compression after impact (CAI) tests with impact energies exceeding 20 J for thermoplastic CFRPs remain scarce. This study examines CAI tests on quasi-isotropic laminates of thermoplastic CFRP, subjected to a low-velocity impact energy of 27.04 J. For comparison, quasi-isotropic laminates of thermoset CFRP were subjected to a low-velocity impact energy of 36.5 J. These tests reveal that the CAI strength of both materials is comparable, notwithstanding the lower fiber volume fraction in the thermoplastic CFRP. Further, this research incorporates a finite element (FE) analysis to investigate the damage mechanisms in thermoplastic CFRP. The FE model, integrating interlaminar damage observed during the impact tests, accurately predicted the relationship between compressive stress and strain, correlating closely with the experimental outcomes. It was observed that both interlaminar and intralaminar damage propagation were constrained until the point of maximum compressive stress. Prior to reaching this maximum, a region of elevated compressive stress in the fiber direction was noted in the 0° layer near the non-impacted side. These findings indicate that the compressive stress in the fiber direction in the 0° layer adjacent to the non-impacted side is pivotal in dictating the final failure, which determines the CAI strength of thermoplastic CFRP laminates.
{"title":"Fracture mechanism of carbon fiber-reinforced thermoplastic composite laminates under compression after impact","authors":"Yoshiko Nagumo, Miyu Hamanaka, Keiichi Shirasu, Kazuki Ryuzono, Akinori Yoshimura, Hironori Tohmyoh, Tomonaga Okabe","doi":"10.1177/00219983241240622","DOIUrl":"https://doi.org/10.1177/00219983241240622","url":null,"abstract":"Thermoplastic carbon fiber-reinforced plastics (CFRPs) are increasingly utilized in the aerospace industry owing to their beneficial properties and enhanced formability relative to thermoset CFRPs. Despite the extensive use of these materials, studies focusing on compression after impact (CAI) tests with impact energies exceeding 20 J for thermoplastic CFRPs remain scarce. This study examines CAI tests on quasi-isotropic laminates of thermoplastic CFRP, subjected to a low-velocity impact energy of 27.04 J. For comparison, quasi-isotropic laminates of thermoset CFRP were subjected to a low-velocity impact energy of 36.5 J. These tests reveal that the CAI strength of both materials is comparable, notwithstanding the lower fiber volume fraction in the thermoplastic CFRP. Further, this research incorporates a finite element (FE) analysis to investigate the damage mechanisms in thermoplastic CFRP. The FE model, integrating interlaminar damage observed during the impact tests, accurately predicted the relationship between compressive stress and strain, correlating closely with the experimental outcomes. It was observed that both interlaminar and intralaminar damage propagation were constrained until the point of maximum compressive stress. Prior to reaching this maximum, a region of elevated compressive stress in the fiber direction was noted in the 0° layer near the non-impacted side. These findings indicate that the compressive stress in the fiber direction in the 0° layer adjacent to the non-impacted side is pivotal in dictating the final failure, which determines the CAI strength of thermoplastic CFRP laminates.","PeriodicalId":15489,"journal":{"name":"Journal of Composite Materials","volume":"11 9 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140127610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-11DOI: 10.1177/00219983241240468
Mushtaq Albdiry
High-density polyethylene (HDPE) has a higher strength-to-density ratio and stiffness but a low branching degree for the packed linear chains that restrict the ability to bond and resist cracking. This study conducts the role of inserting rigid nanoclay (NC) and soft acrylonitrile butadiene styrene (ABS) on the structural, nonlinear fracture toughness and crack resistance of a ternary HDPE/low-density polyethylene-grafted maleic anhydrite (LDPE-g-MA)/ABS blend. Varying additions of 1, 3, 5, and 7 % NC and 5, 10, 15 wt. % ABS were inserted into neat HDPE and HDPE90/LDPE-g-MA10. All materials were hand-mixed before feeding into a single screw extruder and directly melt-blended twice to achieve a good dispersion of nanofiller in the matrix. The structural characteristics and the fracture surfaces of NC/HDPE/LDPE-g-MA and NC/HDPE/LDPE-g-MA/ABS were investigated by TEM, XRD, SEM, and FTIR spectra. Tensile strength and the critical dissipated energy (JIc) determined by quasi-static J-integral fracture mechanic revealed a higher absorbing fracture energy of 75 KJ/m2 for the binary and 85 KJ/m2 for the ternary nanocomposites. The synergistic percolated role of the NC particles and ABS copolymer in front of the crack tip region hinders crack growth for the presence of micro-void coalescence and massive shear-yielding toughening mechanisms.
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