Inspired by the gradient structure of the nature,two gradient lattice structures,i.e.,unidirectional gradient lattice(UGL)and bidirectional gradient lattice(BGL),are proposed based on the body-centered cubic(BCC)latti...Inspired by the gradient structure of the nature,two gradient lattice structures,i.e.,unidirectional gradient lattice(UGL)and bidirectional gradient lattice(BGL),are proposed based on the body-centered cubic(BCC)lattice to obtain specially designed mechanical behaviors,such as load-bearing and energy absorption capacities.First,a theoretical model is proposed to predict the initial stiffness of the gradient lattice structure under compressive loading,and validated against quasi-static compression tests and finite element models(FEMs).The deformation and failure mechanisms of the two structures are further studied based on experiments and simulations.The UGL structure exhibits a layer-by-layer failure mode,which avoids structure-wise shear failure in uniform structures.The BGL structure presents a symmetry deformation pattern,and the failure initiates at the weakest part.Finally,the energy absorption behaviors are also discussed.This study demonstrates the potential application of gradient lattice structures in load-transfer-path modification and energy absorption by topology design.展开更多
基金the National Natural Science Foundation of China(Grant Nos.11972049 and 12002050)National Key Laboratory Foundation of Science and Technology on Materials under Shock and Im-pact(Grant No.6142902200401)Opening Fund of State Key Laboratory of Nonlinear Mechanics.
文摘Inspired by the gradient structure of the nature,two gradient lattice structures,i.e.,unidirectional gradient lattice(UGL)and bidirectional gradient lattice(BGL),are proposed based on the body-centered cubic(BCC)lattice to obtain specially designed mechanical behaviors,such as load-bearing and energy absorption capacities.First,a theoretical model is proposed to predict the initial stiffness of the gradient lattice structure under compressive loading,and validated against quasi-static compression tests and finite element models(FEMs).The deformation and failure mechanisms of the two structures are further studied based on experiments and simulations.The UGL structure exhibits a layer-by-layer failure mode,which avoids structure-wise shear failure in uniform structures.The BGL structure presents a symmetry deformation pattern,and the failure initiates at the weakest part.Finally,the energy absorption behaviors are also discussed.This study demonstrates the potential application of gradient lattice structures in load-transfer-path modification and energy absorption by topology design.
