Biological composites can overcome the conflict between strength and toughness to achieve unprecedented mechanical properties in engineering materials.The suture joint,as a kind of heterogeneous architecture widely ex...Biological composites can overcome the conflict between strength and toughness to achieve unprecedented mechanical properties in engineering materials.The suture joint,as a kind of heterogeneous architecture widely existing in biological tissues,is crucial to connect dissimilar components and to attain a tradeoff of all-sided functional performances.Therefore,the suture joints have attracted many researchers to theoretically investigate their mechanical response.However,most of the previous models focus on the sutural interface between two chemically similar stiff phases with(or without)a thin adhesive layer,which are under the framework of linear elasticity and small deformation.Here,a general model based on the finite deformation framework is proposed to explore the stiffness and toughness of chemically dissimilar suture joints connecting soft and stiff phases.Uniaxial tension tests are conducted to investigate the tensile response of the suture joints,and finite element simulations are implemented to explore the underlying mechanisms,considering both material nonlinearity and cohesive properties of the interface.Two failure modes are quantitively captured by our model.The stored elastic energy in the soft phase competes with the energy dissipation due to the interface debonding,which controls the transition among different failure modes.The toughness of the suture joints depends on not only the intrinsic strengths of the constituent materials and their cohesive strength,but also the interfacial geometry.This work provides the structureproperty relationships of the soft/stiff suture joints and gives a foundational guidance of mechanical design towards high-performance bioinspired composites.展开更多
Investigating natural-inspired applications is a perennially appealing subject for scientists. The current increase in the speed of natural-origin structure growth may be linked to their superior mechanical properties...Investigating natural-inspired applications is a perennially appealing subject for scientists. The current increase in the speed of natural-origin structure growth may be linked to their superior mechanical properties and environmental resilience. Biological composite structures with helicoidal schemes and designs have remarkable capacities to absorb impact energy and withstand damage. However, there is a dearth of extensive study on the influence of fiber redirection and reorientation inside the matrix of a helicoid structure on its mechanical performance and reactivity. The present study aimed to explore the static and transient responses of a bio-inspired helicoid laminated composite(B-iHLC) shell under the influence of an explosive load using an isomorphic method. The structural integrity of the shell is maintained by a viscoelastic basis known as the Pasternak foundation, which encompasses two coefficients of stiffness and one coefficient of damping. The equilibrium equations governing shell dynamics are obtained by using Hamilton's principle and including the modified first-order shear theory,therefore obviating the need to employ a shear correction factor. The paper's model and approach are validated by doing numerical comparisons with respected publications. The findings of this study may be used in the construction of military and civilian infrastructure in situations when the structure is subjected to severe stresses that might potentially result in catastrophic collapse. The findings of this paper serve as the foundation for several other issues, including geometric optimization and the dynamic response of similar mechanical structures.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12002032,11572002,and 12002006)。
文摘Biological composites can overcome the conflict between strength and toughness to achieve unprecedented mechanical properties in engineering materials.The suture joint,as a kind of heterogeneous architecture widely existing in biological tissues,is crucial to connect dissimilar components and to attain a tradeoff of all-sided functional performances.Therefore,the suture joints have attracted many researchers to theoretically investigate their mechanical response.However,most of the previous models focus on the sutural interface between two chemically similar stiff phases with(or without)a thin adhesive layer,which are under the framework of linear elasticity and small deformation.Here,a general model based on the finite deformation framework is proposed to explore the stiffness and toughness of chemically dissimilar suture joints connecting soft and stiff phases.Uniaxial tension tests are conducted to investigate the tensile response of the suture joints,and finite element simulations are implemented to explore the underlying mechanisms,considering both material nonlinearity and cohesive properties of the interface.Two failure modes are quantitively captured by our model.The stored elastic energy in the soft phase competes with the energy dissipation due to the interface debonding,which controls the transition among different failure modes.The toughness of the suture joints depends on not only the intrinsic strengths of the constituent materials and their cohesive strength,but also the interfacial geometry.This work provides the structureproperty relationships of the soft/stiff suture joints and gives a foundational guidance of mechanical design towards high-performance bioinspired composites.
文摘Investigating natural-inspired applications is a perennially appealing subject for scientists. The current increase in the speed of natural-origin structure growth may be linked to their superior mechanical properties and environmental resilience. Biological composite structures with helicoidal schemes and designs have remarkable capacities to absorb impact energy and withstand damage. However, there is a dearth of extensive study on the influence of fiber redirection and reorientation inside the matrix of a helicoid structure on its mechanical performance and reactivity. The present study aimed to explore the static and transient responses of a bio-inspired helicoid laminated composite(B-iHLC) shell under the influence of an explosive load using an isomorphic method. The structural integrity of the shell is maintained by a viscoelastic basis known as the Pasternak foundation, which encompasses two coefficients of stiffness and one coefficient of damping. The equilibrium equations governing shell dynamics are obtained by using Hamilton's principle and including the modified first-order shear theory,therefore obviating the need to employ a shear correction factor. The paper's model and approach are validated by doing numerical comparisons with respected publications. The findings of this study may be used in the construction of military and civilian infrastructure in situations when the structure is subjected to severe stresses that might potentially result in catastrophic collapse. The findings of this paper serve as the foundation for several other issues, including geometric optimization and the dynamic response of similar mechanical structures.
