摘要
This study details an investigation of the viscoelastic behavior of some biomaterials （nacre, cattle horn and beetle cuticle） at lamellar length scales using quasi-static and dynamic nanoindentation techniques in the materials＇ Transverse Direction （TD） and Longitudinal Direction （LD）. Our results show that nacre exhibits high fracture toughness moving towards a larger cam- paniForm as the stress frequency varies from 10 Hz to 200 Hz. Elytra cuticle exhibits the least fracture toughness presenting little energy dissipation in TD. It was initially speculated that the fracture toughness of the subject materials would be directly related to energy-dissipating mechanisms （mechanical hysteresis）, but not the maximum value of the loss tangent tan＆ However, it was found that the materials＇ elastic modulus and hardness are similar in both the TD and LD when assessed using the quasi-static nanoindentation method, but not dynamic nanoindentation. It is believed that the reported results can be useful in the design of new crack arrest and damping materials based on biological counterparts.
This study details an investigation of the viscoelastic behavior of some biomaterials （nacre, cattle horn and beetle cuticle） at lamellar length scales using quasi-static and dynamic nanoindentation techniques in the materials＇ Transverse Direction （TD） and Longitudinal Direction （LD）. Our results show that nacre exhibits high fracture toughness moving towards a larger cam- paniForm as the stress frequency varies from 10 Hz to 200 Hz. Elytra cuticle exhibits the least fracture toughness presenting little energy dissipation in TD. It was initially speculated that the fracture toughness of the subject materials would be directly related to energy-dissipating mechanisms （mechanical hysteresis）, but not the maximum value of the loss tangent tan＆ However, it was found that the materials＇ elastic modulus and hardness are similar in both the TD and LD when assessed using the quasi-static nanoindentation method, but not dynamic nanoindentation. It is believed that the reported results can be useful in the design of new crack arrest and damping materials based on biological counterparts.
基金
the National Natural Science Foundation of China，the National Science & Technology Pillar Program of China in the Twelfth Five-Year Plan Period，the Development Program of Science and Technology of Jilin Province of China，the "Project 985" of Jilin University
