Pub Date : 2024-08-17DOI: 10.1177/10996362241275532
Mojtaba Mohammadpour, Fathollah Taheri-Behrooz
Auxetic structures possess negative Poisson’s ratio (NPR). They exhibit enhanced indentation resistance, synclastic deformation, high fracture toughness and high energy absorption. Several sorts of auxetic structures exist, such as re-entrant, arrowhead, chiral, etc. The re-entrant structure is the most common sort of auxetic structures. This paper investigates the mechanical behavior of the re-entrant auxetic structure using experimental and numerical methods. Two modified re-entrant topologies are proposed based on the original (conventional) re-entrant topology. Using these modified topologies, two re-entrant auxetic sandwich structures are designed and 3D printed using fused deposition modeling (FDM) out of polylactic acid (PLA). Conducting compression, three and four-point bending tests, the compressive and flexural performance of the two new re-entrant auxetic sandwich structures is studied and compared with the original (conventional) re-entrant structure. More specifically, Poisson’s ratio, compressive modulus, flexural stiffness and maximum loads of the structures are focused and studied. The mechanical properties of auxetic sandwich structures are improved using modified topologies. The new re-entrant auxetic sandwich structures show 11% higher normalized compressive modulus and 9% higher normalized flexural stiffness than the original re-entrant structure.
{"title":"Compressive and flexural responses of auxetic sandwich panels with modified re-entrant honeycomb cores","authors":"Mojtaba Mohammadpour, Fathollah Taheri-Behrooz","doi":"10.1177/10996362241275532","DOIUrl":"https://doi.org/10.1177/10996362241275532","url":null,"abstract":"Auxetic structures possess negative Poisson’s ratio (NPR). They exhibit enhanced indentation resistance, synclastic deformation, high fracture toughness and high energy absorption. Several sorts of auxetic structures exist, such as re-entrant, arrowhead, chiral, etc. The re-entrant structure is the most common sort of auxetic structures. This paper investigates the mechanical behavior of the re-entrant auxetic structure using experimental and numerical methods. Two modified re-entrant topologies are proposed based on the original (conventional) re-entrant topology. Using these modified topologies, two re-entrant auxetic sandwich structures are designed and 3D printed using fused deposition modeling (FDM) out of polylactic acid (PLA). Conducting compression, three and four-point bending tests, the compressive and flexural performance of the two new re-entrant auxetic sandwich structures is studied and compared with the original (conventional) re-entrant structure. More specifically, Poisson’s ratio, compressive modulus, flexural stiffness and maximum loads of the structures are focused and studied. The mechanical properties of auxetic sandwich structures are improved using modified topologies. The new re-entrant auxetic sandwich structures show 11% higher normalized compressive modulus and 9% higher normalized flexural stiffness than the original re-entrant structure.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"34 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188220","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 : 2024-08-12DOI: 10.1177/10996362241249033
Xin Liu, Jize Mao, Jia Qu, Houqi Yao
Hail presents a significant threat to the structural integrity of aircraft, particularly with the extensive use of foam sandwich structures in aerospace applications. Therefore, it is crucial to consider the effects of hail impact on foam sandwich structures. This paper aims to investigate the impact of ice projectiles on carbon Fiber/PMI foam sandwich structures, using both experimental and numerical simulation approaches. The gas cannon was employed to launch ice projectiles, which were then directed towards the carbon Fiber/PMI foam sandwich structures. Additionally, a numerical simulation model was developed using ANSYS/LS-DYNA software to analyse the impact of these ice projectiles. Moreover, the validity of the finite element model was confirmed through experimental verification. The study involves simulations of single-point continuous impacts of ice projectiles and multi-point simultaneous impacts on carbon Fiber/PMI foam sandwich structures, while maintaining the same total impact energy. By varying the distribution of ice projectiles, the dynamic response and damage characteristics of the target plate are analysed. Specifically, the research aims to investigative the deformation characteristics of the target plate and the energy absorption of the structure. The research results underscore the importance of considering the distribution of ice projectiles in mitigating structural damage caused by hail impact.
{"title":"Dynamic response of foam sandwich structures under multiple ice projectiles impacts at high velocity","authors":"Xin Liu, Jize Mao, Jia Qu, Houqi Yao","doi":"10.1177/10996362241249033","DOIUrl":"https://doi.org/10.1177/10996362241249033","url":null,"abstract":"Hail presents a significant threat to the structural integrity of aircraft, particularly with the extensive use of foam sandwich structures in aerospace applications. Therefore, it is crucial to consider the effects of hail impact on foam sandwich structures. This paper aims to investigate the impact of ice projectiles on carbon Fiber/PMI foam sandwich structures, using both experimental and numerical simulation approaches. The gas cannon was employed to launch ice projectiles, which were then directed towards the carbon Fiber/PMI foam sandwich structures. Additionally, a numerical simulation model was developed using ANSYS/LS-DYNA software to analyse the impact of these ice projectiles. Moreover, the validity of the finite element model was confirmed through experimental verification. The study involves simulations of single-point continuous impacts of ice projectiles and multi-point simultaneous impacts on carbon Fiber/PMI foam sandwich structures, while maintaining the same total impact energy. By varying the distribution of ice projectiles, the dynamic response and damage characteristics of the target plate are analysed. Specifically, the research aims to investigative the deformation characteristics of the target plate and the energy absorption of the structure. The research results underscore the importance of considering the distribution of ice projectiles in mitigating structural damage caused by hail impact.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"42 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141935588","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}
Owing to the ability of negative Poisson’s ratio (NPR) structures in enhancing the stiffening effectof shear stiffening gels (SSG), combining the two in cushioning applications has attracted much attention. This paper presents the design of NPR flexible cushioning sandwich composites featuring a double-arrow structure (DAS). The DAS is optimized using a modified genetic algorithm, and the cohesive property is leveraged to reinforce the stiffening effect of SSG, thereby improving the material’s cushioning efficiency. The synergistic effect of the DAS and SSG and the law of SSG arrangement on the energy absorption efficiency of cushioning were revealed using the finite element method and experiment. It can be found that the size effect of the DAS significantly contributed to the enhancement of the energy-absorption efficiency of the SSG stiffening. In double-arrow sandwich composite (DASC), the larger reversed-triangle deformation and the increased number of reversed-triangle configurations, amplified the shear stiffening of the SSG, improving the impact load dissipation and energy absorption efficiency of sandwich composite. The energy absorption efficiency of the DASC was improved owing to the synergistic effect of the DAS cohesive effect and the SSG stiffening properties, with the energy absorption ratio and mass specific energy absorption increased by 83.02% and 136% compared to neat polyurethane. The DASC optimized in this study has good flexibility and energy absorption capacity and is promising for application in the field of flexible protection.
由于负泊松比（NPR）结构能够增强剪切加劲凝胶（SSG）的加劲效果，因此将二者结合起来应用于缓冲领域备受关注。本文介绍了具有双箭头结构（DAS）的 NPR 柔性缓冲夹层复合材料的设计。利用改进的遗传算法对 DAS 进行了优化，并利用其内聚特性加强了 SSG 的加硬效果，从而提高了材料的缓冲效率。利用有限元方法和实验揭示了 DAS 和 SSG 的协同效应以及 SSG 排列对缓冲能量吸收效率的影响规律。研究发现，DAS的尺寸效应对SSG加劲层能量吸收效率的提高有明显的促进作用。在双箭夹芯复合材料（DASC）中，较大的反转三角形变形和增加的反转三角形构型数量放大了 SSG 的剪切刚化，提高了夹芯复合材料的冲击载荷耗散和能量吸收效率。由于 DAS 内聚效应和 SSG 加劲性能的协同作用，DASC 的能量吸收效率得到了提高，与纯聚氨酯相比，能量吸收比和质量比能量吸收分别提高了 83.02% 和 136%。本研究优化的 DASC 具有良好的柔韧性和能量吸收能力，有望应用于柔性保护领域。
{"title":"Cushioning property and structure optimization of double-arrow sandwich composite based on modified genetic algorithm","authors":"Jian Zhang, Qian Jiang, Feng Zhao, Kanghui Zhou, Zhenqian Lu, Shengkai Liu, Liwei Wu","doi":"10.1177/10996362241272834","DOIUrl":"https://doi.org/10.1177/10996362241272834","url":null,"abstract":"Owing to the ability of negative Poisson’s ratio (NPR) structures in enhancing the stiffening effectof shear stiffening gels (SSG), combining the two in cushioning applications has attracted much attention. This paper presents the design of NPR flexible cushioning sandwich composites featuring a double-arrow structure (DAS). The DAS is optimized using a modified genetic algorithm, and the cohesive property is leveraged to reinforce the stiffening effect of SSG, thereby improving the material’s cushioning efficiency. The synergistic effect of the DAS and SSG and the law of SSG arrangement on the energy absorption efficiency of cushioning were revealed using the finite element method and experiment. It can be found that the size effect of the DAS significantly contributed to the enhancement of the energy-absorption efficiency of the SSG stiffening. In double-arrow sandwich composite (DASC), the larger reversed-triangle deformation and the increased number of reversed-triangle configurations, amplified the shear stiffening of the SSG, improving the impact load dissipation and energy absorption efficiency of sandwich composite. The energy absorption efficiency of the DASC was improved owing to the synergistic effect of the DAS cohesive effect and the SSG stiffening properties, with the energy absorption ratio and mass specific energy absorption increased by 83.02% and 136% compared to neat polyurethane. The DASC optimized in this study has good flexibility and energy absorption capacity and is promising for application in the field of flexible protection.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"54 79 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141935587","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 : 2024-08-04DOI: 10.1177/10996362241272792
Peihong Liu, Wen Qi, Ketong Luo, Cailiu Yin, Jiayao Li, Chun Lu, Lina Lu
In this paper, a novel hybrid triply periodic minimal surface (TPMS) core with a nonlinear transition region was designed by combining two types of TPMS (Diamond and Schwarz P) structures using the sigmoid function. The width of the transition region was precisely regulated by adjusting the gradient control parameter r in the sigmoid function. Composite sandwich structures (CSS) were fabricated by bonding two carbon fiber reinforced polymer (CFRP) face sheets to a 3D printed polylactic acid (PLA) core. The bending performance and failure mechanisms of the CSSs with the hybrid TPMS cores were analyzed through three-point bending tests and finite element analysis (FEA). The results indicate that as r increases, the transition region of the hybrid TPMS cores becomes narrower, leading to a gradual decrease in bending strength, bending stiffness, and core shear stress. The failure process of the CSSs in the experiment aligns well with the FEA results. Through comparative analysis of the stiffness-to-weight and strength-to-weight ratios of the CSSs with the native TPMS cores, the hybrid TPMS cores with a wider transition region enhance the structural efficiency of the CSSs, while those with a narrower transition region negatively impact the performance of the CSSs.
{"title":"Bending performance and failure mechanisms of composite sandwich structures with 3D printed hybrid triply periodic minimal surface cores","authors":"Peihong Liu, Wen Qi, Ketong Luo, Cailiu Yin, Jiayao Li, Chun Lu, Lina Lu","doi":"10.1177/10996362241272792","DOIUrl":"https://doi.org/10.1177/10996362241272792","url":null,"abstract":"In this paper, a novel hybrid triply periodic minimal surface (TPMS) core with a nonlinear transition region was designed by combining two types of TPMS (Diamond and Schwarz P) structures using the sigmoid function. The width of the transition region was precisely regulated by adjusting the gradient control parameter r in the sigmoid function. Composite sandwich structures (CSS) were fabricated by bonding two carbon fiber reinforced polymer (CFRP) face sheets to a 3D printed polylactic acid (PLA) core. The bending performance and failure mechanisms of the CSSs with the hybrid TPMS cores were analyzed through three-point bending tests and finite element analysis (FEA). The results indicate that as r increases, the transition region of the hybrid TPMS cores becomes narrower, leading to a gradual decrease in bending strength, bending stiffness, and core shear stress. The failure process of the CSSs in the experiment aligns well with the FEA results. Through comparative analysis of the stiffness-to-weight and strength-to-weight ratios of the CSSs with the native TPMS cores, the hybrid TPMS cores with a wider transition region enhance the structural efficiency of the CSSs, while those with a narrower transition region negatively impact the performance of the CSSs.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"115 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141935589","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 : 2024-07-25DOI: 10.1177/10996362241262948
Timothy L Grondin, Ali P Gordon, Denizhan Yavas
Sandwich composite structures have been widely used in aerospace and marine applications for many years due to their remarkable specific strength and stiffness. Despite their widespread use, there has been a constant effort to further improve their mechanical properties. This investigation delves into the influence of a Functionally Graded (FG) core, inspired by nature, in the enhancement of flexural properties of additively manufactured sandwich beams. The design space of the proposed sandwich beam with FG core of cellular cells in triangular shape is explored using an analytical formulation combining the Euler-Bernoulli theory and the Gibson-Ashby approach to develop a flexural performance index. The study involves examining a linear variation of the core density. To validate the analytical predictions, linear-elastic Finite Element (FE) models are created in the ABAQUS commercial FE program. Subsequently, the sandwich beams with FG core are additively manufactured using a polyjet printer (Stratasys J55), eliminates the need for secondary bonding between the face sheet and core. Two different build orientations are examined to investigate the influence of build orientation on flexural properties. The numerical and experimental results closely align with the analytical findings, indicating an approximate 31% increase in the performance index with the FG core. Noteworthy is that sandwich beams featuring FG cores exhibits a progressive failure, whereas those with uniform cores displayed sudden and catastrophic failure. As a result, the suggested FG core design not only contributes to a slight improvement in energy absorption capacity but, more significantly, displays fail-safe failure characteristics. These findings present significant potential for high-performance, lightweight sandwich structures in aerospace and biomedical applications.
{"title":"Exploring flexural behavior of additively manufactured sandwich beams with bioinspired functionally graded cores","authors":"Timothy L Grondin, Ali P Gordon, Denizhan Yavas","doi":"10.1177/10996362241262948","DOIUrl":"https://doi.org/10.1177/10996362241262948","url":null,"abstract":"Sandwich composite structures have been widely used in aerospace and marine applications for many years due to their remarkable specific strength and stiffness. Despite their widespread use, there has been a constant effort to further improve their mechanical properties. This investigation delves into the influence of a Functionally Graded (FG) core, inspired by nature, in the enhancement of flexural properties of additively manufactured sandwich beams. The design space of the proposed sandwich beam with FG core of cellular cells in triangular shape is explored using an analytical formulation combining the Euler-Bernoulli theory and the Gibson-Ashby approach to develop a flexural performance index. The study involves examining a linear variation of the core density. To validate the analytical predictions, linear-elastic Finite Element (FE) models are created in the ABAQUS commercial FE program. Subsequently, the sandwich beams with FG core are additively manufactured using a polyjet printer (Stratasys J55), eliminates the need for secondary bonding between the face sheet and core. Two different build orientations are examined to investigate the influence of build orientation on flexural properties. The numerical and experimental results closely align with the analytical findings, indicating an approximate 31% increase in the performance index with the FG core. Noteworthy is that sandwich beams featuring FG cores exhibits a progressive failure, whereas those with uniform cores displayed sudden and catastrophic failure. As a result, the suggested FG core design not only contributes to a slight improvement in energy absorption capacity but, more significantly, displays fail-safe failure characteristics. These findings present significant potential for high-performance, lightweight sandwich structures in aerospace and biomedical applications.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"4 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771054","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 : 2024-05-30DOI: 10.1177/10996362241257057
Yan Wang, Xingyu Wei, Zhibin Li, Xiaohan Tang, Jian Xiong
This research aims to improve the performance of low-density carbon fiber composite honeycomb structures by optimizing their geometric design. To improve buckling resistance, a curved-wall carbon fiber reinforced polymer (CFRP) honeycomb is designed by substituting the curved walls with circular cross sections for the straight edges of traditional hexagonal honeycomb. The honeycomb was fabricated using the modified tailor-folding method. The deformation and failure modes of curved-wall CFRP honeycomb were investigated by analytical model, experiments and finite element analysis (FEA). The analytical model demonstrated a satisfactory correlation with the experimental results and simulations. The specific strength was employed to investigate the load-weight efficiency of curved-wall CFRP honeycomb under different geometric parameters, aiming to identify the most optimal lightweight structure configuration. The results revealed that the central angle of the circular arc significantly influenced the buckling resistance of honeycomb, and an optimal combination of geometric parameters with specific strength was obtained. This study can serve as a guide for designing and optimizing lightweight structures.
{"title":"Fabrication and buckling resistance behaviors of curved-wall CFRP honeycomb sandwich structure under out-of-plane compression","authors":"Yan Wang, Xingyu Wei, Zhibin Li, Xiaohan Tang, Jian Xiong","doi":"10.1177/10996362241257057","DOIUrl":"https://doi.org/10.1177/10996362241257057","url":null,"abstract":"This research aims to improve the performance of low-density carbon fiber composite honeycomb structures by optimizing their geometric design. To improve buckling resistance, a curved-wall carbon fiber reinforced polymer (CFRP) honeycomb is designed by substituting the curved walls with circular cross sections for the straight edges of traditional hexagonal honeycomb. The honeycomb was fabricated using the modified tailor-folding method. The deformation and failure modes of curved-wall CFRP honeycomb were investigated by analytical model, experiments and finite element analysis (FEA). The analytical model demonstrated a satisfactory correlation with the experimental results and simulations. The specific strength was employed to investigate the load-weight efficiency of curved-wall CFRP honeycomb under different geometric parameters, aiming to identify the most optimal lightweight structure configuration. The results revealed that the central angle of the circular arc significantly influenced the buckling resistance of honeycomb, and an optimal combination of geometric parameters with specific strength was obtained. This study can serve as a guide for designing and optimizing lightweight structures.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"42 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141196184","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 : 2024-05-29DOI: 10.1177/10996362241257789
Zhiqiang Zhang, Peng Lin, Dayong Hu
Inspired by brain corals and cuttlebone, this study employed 3D printing technology to fabricate a novel bio-inspired multilayer sandwich structure based on the Hilbert space-filling curve (named BHSS). The mechanical behavior and deformation process of the BHSS were compared through quasi-static axial crushing experiments and finite element (FE) simulations. The energy absorbing characteristics of the BHSS with different layers were compared through FE simulations, and the results indicated that the 4-layer BHSS displayed superior crashworthiness. Then, parametric studies were conducted to investigate the influence of layer-height gradient and wall-thickness gradient on the energy absorption performance and deformation modes of the BHSS. It was confirmed that the double gradient designs significantly reduced the initial peak force and improved the specific energy absorption of the BHSS. Finally, the multi-objectives optimization based on response surface method and the non-dominated sorting genetic algorithm (NSGA-II) was employed to optimize the geometric parameters of the BHSS, aiming at the optimal configuration for better crashworthiness. Compared to the original design structure, the SEA of the optimized knee point structure was increased by 21.8% and the IPF was reduced by 72.6%. These findings provided valuable guidelines for the brain-coral-inspired design of multilayer sandwich structures with superior energy-absorbing performance.
{"title":"Crashworthiness analysis and optimization of brain-coral-inspired multilayer sandwich structures under axial crushing","authors":"Zhiqiang Zhang, Peng Lin, Dayong Hu","doi":"10.1177/10996362241257789","DOIUrl":"https://doi.org/10.1177/10996362241257789","url":null,"abstract":"Inspired by brain corals and cuttlebone, this study employed 3D printing technology to fabricate a novel bio-inspired multilayer sandwich structure based on the Hilbert space-filling curve (named BHSS). The mechanical behavior and deformation process of the BHSS were compared through quasi-static axial crushing experiments and finite element (FE) simulations. The energy absorbing characteristics of the BHSS with different layers were compared through FE simulations, and the results indicated that the 4-layer BHSS displayed superior crashworthiness. Then, parametric studies were conducted to investigate the influence of layer-height gradient and wall-thickness gradient on the energy absorption performance and deformation modes of the BHSS. It was confirmed that the double gradient designs significantly reduced the initial peak force and improved the specific energy absorption of the BHSS. Finally, the multi-objectives optimization based on response surface method and the non-dominated sorting genetic algorithm (NSGA-II) was employed to optimize the geometric parameters of the BHSS, aiming at the optimal configuration for better crashworthiness. Compared to the original design structure, the SEA of the optimized knee point structure was increased by 21.8% and the IPF was reduced by 72.6%. These findings provided valuable guidelines for the brain-coral-inspired design of multilayer sandwich structures with superior energy-absorbing performance.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"53 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141195656","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 : 2024-04-30DOI: 10.1177/10996362241251808
Ehsan Naeiji, Hamed Afrasiab
Sandwich pipes are widely used in various piping applications owing to their exceptional pressure resistance and thermal insulation properties. In this paper, the mechanical properties and loading performance of sandwich pipes made of polypropylene material have been investigated under different loading conditions including lateral and axial compression, as well as hydrostatic internal and external pressures. For this purpose, finite element models of sandwich pipes with various designs have been developed. Material properties have been determined through standard experimental tests, and the finite element models have been validated using lateral compression experiments. The results indicate that incorporating annular cores with thinner thickness and greater numbers, along with using a thicker inner pipe in the sandwich pipe structure, improves its properties and performance.
{"title":"Analyzing mechanical properties and loading performance of polypropylene sandwich pipes","authors":"Ehsan Naeiji, Hamed Afrasiab","doi":"10.1177/10996362241251808","DOIUrl":"https://doi.org/10.1177/10996362241251808","url":null,"abstract":"Sandwich pipes are widely used in various piping applications owing to their exceptional pressure resistance and thermal insulation properties. In this paper, the mechanical properties and loading performance of sandwich pipes made of polypropylene material have been investigated under different loading conditions including lateral and axial compression, as well as hydrostatic internal and external pressures. For this purpose, finite element models of sandwich pipes with various designs have been developed. Material properties have been determined through standard experimental tests, and the finite element models have been validated using lateral compression experiments. The results indicate that incorporating annular cores with thinner thickness and greater numbers, along with using a thicker inner pipe in the sandwich pipe structure, improves its properties and performance.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"80 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140827093","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 : 2024-04-29DOI: 10.1177/10996362241249683
Alexander V Lopatin, Evgeny V Morozov
Results of the study of symmetrical facing wrinkling of compressed rectangular composite sandwich plates with orthotropic faces and core are presented in the paper. Two parallel edges of the plate facings are simply supported, one edge is clamped, and another edge is free (SSCF). The wrinkling problem is solved using the Ritz method in which the total energy functional of plate faces and core is obtained based on the original model, considering nonlinear variation of the transverse displacement of the core material from the value of facing’s deflection to zero. Application of the Ritz method yields formulas for the calculation of critical compressive load. The critical load is found using a minimization with respect to the parameter of the wrinkling waves evolution and the parameter characterizing the rate of fading of the transverse displacement. Based on the derived formulas, the effects of facing and core thicknesses, and modulus elasticity of core material on the critical wrinkling load are studied. The results of calculations are verified using a finite element analysis. It is shown that the value of critical load calculated based on the proposed model is more accurate compared to that calculated using the Winkler-Pasternak model, particularly for the sandwich plates with thin faces and thick core.
{"title":"Symmetrical wrinkling of compressed composite SSCF facings of a rectangular sandwich plate","authors":"Alexander V Lopatin, Evgeny V Morozov","doi":"10.1177/10996362241249683","DOIUrl":"https://doi.org/10.1177/10996362241249683","url":null,"abstract":"Results of the study of symmetrical facing wrinkling of compressed rectangular composite sandwich plates with orthotropic faces and core are presented in the paper. Two parallel edges of the plate facings are simply supported, one edge is clamped, and another edge is free (SSCF). The wrinkling problem is solved using the Ritz method in which the total energy functional of plate faces and core is obtained based on the original model, considering nonlinear variation of the transverse displacement of the core material from the value of facing’s deflection to zero. Application of the Ritz method yields formulas for the calculation of critical compressive load. The critical load is found using a minimization with respect to the parameter of the wrinkling waves evolution and the parameter characterizing the rate of fading of the transverse displacement. Based on the derived formulas, the effects of facing and core thicknesses, and modulus elasticity of core material on the critical wrinkling load are studied. The results of calculations are verified using a finite element analysis. It is shown that the value of critical load calculated based on the proposed model is more accurate compared to that calculated using the Winkler-Pasternak model, particularly for the sandwich plates with thin faces and thick core.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"10 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140827090","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 : 2024-04-06DOI: 10.1177/10996362241245531
Xu Zhang, Benzhi Min, Shouji Zhao, Qiang Fu, Di Zhang, Zhenqing Wang
Turtle shells have evolved over millions of years, developing exceptional mechanical properties such as high relative strength and toughness, rendering them highly effective in resisting impacts. This study delves into the impact resistance of bionic turtle shell structures with various suture shapes. This article analyzes the low-velocity impact of carbon fiber epoxy resin prepreg (CF/EP) composite sandwich panels with a suture interface by using the finite element simulation. The simulations encompass closed and unclosed models featuring bonded and unbonded tips, each with diverse trapezoidal geometries (triangular, trapezoidal, anti-trapezoidal, and rectangular). The findings reveal that sandwich structures with suture interfaces demonstrate significantly enhanced impact resistance compared to those lacking sutures, displaying 3–9 times greater deformation capacity and 20–30 times higher energy absorption capacity. The impact resistance of the triangular suture interface exceeded that of other bioinspired suture shapes, with trapezoidal and anti-trapezoidal sutures also enhancing stiffness, strength, and toughness. Additionally, a 6° bonded tip angle resulted in optimal performance for the triangular suture interface across all analyzed perspectives. The simulation study in this paper provides comprehensive and reliable data on low-velocity impact results, offering fundamental insights for researchers to design composite material structures that meet specific mechanical requirements effectively. Additionally, it offers novel ideas for the connection of protective structures, such as artificial armor.
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