讲座题目：An Indentation Test Technique for Soft Materials with Direct Contact Area Measurements

报告人：Professor Wei Tong

时 间：5月19日（周四）下午2:00~3:00
地 点：大风洞会议室
主持人：熊春阳（副教授）

报告内容摘要：
    Indentation tests have been widely used for characterizing mechanical properties of various engineering materials and are increasingly being applied for biological materials such as soft tissues as well. Due to the large nonlinear deformation of soft materials under indentation, possible pile-up or sink-in may exist at the vicinity of the indent. For metallic materials undergoing plastic deformation, a post-mortem examination of the indent shape can be carried out to estimate the magnitude of the pile-up or sink-in so certain corrections can be applied to the indentation test data. For soft tissues exhibiting mostly visco-hyperelastic deformation behavior, such a post-mortem examination is almost impossible as the indent will almost completely recover upon unloading.
     In this talk, we present an indentation test technique for soft materials and tissues with a capability of directly measuring the contact area under the indenter while the load remains imposed. Key aspects of the technique include the use of a stationary, transparent indenter, a digital microscope, and a special indentation loading apparatus that moves the test materials towards the indenter. Elastomeric materials are used to validate the test methodology and the additional measurement data of the contact area under load are used to critically evaluate the possible hyperelastic material models for the materials tested. Application examples are also presented for some anisotropic soft materials using the novel indentation test.