In high-performance electric sports vehicles,the application of woven composite materials with the purpose of lightweight has become an inevitable choice.It is considerably difference between traditional metal materia...In high-performance electric sports vehicles,the application of woven composite materials with the purpose of lightweight has become an inevitable choice.It is considerably difference between traditional metal materials and composites for the lightweight design strategy of electric vehicle structures,due to the multi-scale and anisotropic characteristics of fiber reinforced composites.Nevertheless,most of scholars are focus on the meso-scale mechanical responses of woven composites,and few studies are involved in their multi-scale mechanical behaviors and hierarchical design strategy of composite structures in electric vehicles.In this work,a multiscale analysis strategy was proposed to investigate mechanical behaviors of composite front firewall.Subsequently,a hierarchical optimization strategy with the objective of lightweight design of composite front firewall was carried out.Finally,a reasonable layout scheme of composite front firewall was quantitatively obtained.The maximum errors between the predicted and theoretical/experimental results in terms of equivalent engineering constants of fiber yarns and 2D twill woven composites(2DTWCs)were 8.8 GPa and 7%,respectively.It indicates that the multi-scale models can be used to evaluate the mechanical properties of 2DTWCs.Additionally,the total weight of optimized composite front firewall was reduced by 36%in comparison with the reference,and simultaneously the total stiffness was improved by 26%.Hence,it is an effective strategy to design lightweight composite structures of electric vehicles.We hope the proposed multi-scale and hierarchical design strategy could promote the further development of composite structures in high-performance electric sports vehicles.展开更多
Natural mechanical materials,such as bamboo and bone,often exhibit superior specific mechanical properties due to their hierarchical porous architectures.Using the principle of hierarchy as inspiration can facilitate ...Natural mechanical materials,such as bamboo and bone,often exhibit superior specific mechanical properties due to their hierarchical porous architectures.Using the principle of hierarchy as inspiration can facilitate the development of hierarchical mechanical metamaterials(HMMs)across multiple length scales via 3D printing.In this work,we propose self-similar HMMs that combine octet-truss(OCT)architecture as the first and second orders,with cubic architecture as the third or more orders.These HMMs were fabricated using stereolithography 3D printing,with the length sizes ranging from approximately 200µm to the centimeter scale.The compressive stress–strain behaviors of HMMs exhibit a zigzag characteristic,and the toughness and energy absorption can be significantly enhanced by the hierarchical architecture.The compressive moduli are comparable to that of natural materials,and the strengths are superior to that of most polymer/metal foams,alumina hollow/carbon lattices,and other natural materials.Furthermore,the flexural stress–strain curves exhibit a nonlinear behavior,which can be attributed to the hierarchical architecture and local damage propagation.The relatively high mechanical properties can be attributed to the synergistic effect of the stretch-dominated OCT architecture and the bending-dominated cube architecture.Lastly,an ultralight HMM-integrated unmanned aerial vehicle(HMM-UAV)was successfully designed and printed.The HMM-UAV is~85%lighter than its bulk counterpart,remarkably extending the flight duration time(~53%).This work not only provides an effective design strategy for HMMs but also further expands the application benchmark of HMMs.展开更多
基金supported in part by the major scientific and technological project of Shenzhen Municipal Science,Technology and Innovation Bureau(KJZD20230923114259049)National Key R&D Program of China(2023YFB2504605).
文摘In high-performance electric sports vehicles,the application of woven composite materials with the purpose of lightweight has become an inevitable choice.It is considerably difference between traditional metal materials and composites for the lightweight design strategy of electric vehicle structures,due to the multi-scale and anisotropic characteristics of fiber reinforced composites.Nevertheless,most of scholars are focus on the meso-scale mechanical responses of woven composites,and few studies are involved in their multi-scale mechanical behaviors and hierarchical design strategy of composite structures in electric vehicles.In this work,a multiscale analysis strategy was proposed to investigate mechanical behaviors of composite front firewall.Subsequently,a hierarchical optimization strategy with the objective of lightweight design of composite front firewall was carried out.Finally,a reasonable layout scheme of composite front firewall was quantitatively obtained.The maximum errors between the predicted and theoretical/experimental results in terms of equivalent engineering constants of fiber yarns and 2D twill woven composites(2DTWCs)were 8.8 GPa and 7%,respectively.It indicates that the multi-scale models can be used to evaluate the mechanical properties of 2DTWCs.Additionally,the total weight of optimized composite front firewall was reduced by 36%in comparison with the reference,and simultaneously the total stiffness was improved by 26%.Hence,it is an effective strategy to design lightweight composite structures of electric vehicles.We hope the proposed multi-scale and hierarchical design strategy could promote the further development of composite structures in high-performance electric sports vehicles.
基金financial support of the National Natural Science Foundation of China(Grant No.51905350).
文摘Natural mechanical materials,such as bamboo and bone,often exhibit superior specific mechanical properties due to their hierarchical porous architectures.Using the principle of hierarchy as inspiration can facilitate the development of hierarchical mechanical metamaterials(HMMs)across multiple length scales via 3D printing.In this work,we propose self-similar HMMs that combine octet-truss(OCT)architecture as the first and second orders,with cubic architecture as the third or more orders.These HMMs were fabricated using stereolithography 3D printing,with the length sizes ranging from approximately 200µm to the centimeter scale.The compressive stress–strain behaviors of HMMs exhibit a zigzag characteristic,and the toughness and energy absorption can be significantly enhanced by the hierarchical architecture.The compressive moduli are comparable to that of natural materials,and the strengths are superior to that of most polymer/metal foams,alumina hollow/carbon lattices,and other natural materials.Furthermore,the flexural stress–strain curves exhibit a nonlinear behavior,which can be attributed to the hierarchical architecture and local damage propagation.The relatively high mechanical properties can be attributed to the synergistic effect of the stretch-dominated OCT architecture and the bending-dominated cube architecture.Lastly,an ultralight HMM-integrated unmanned aerial vehicle(HMM-UAV)was successfully designed and printed.The HMM-UAV is~85%lighter than its bulk counterpart,remarkably extending the flight duration time(~53%).This work not only provides an effective design strategy for HMMs but also further expands the application benchmark of HMMs.
