基于球压痕法的玻璃材料强度原位快速表征技术

Fast in-situ characterization for glass materials strength by spherical indentation method

提出基于球压技术的玻璃材料强度原位快速表征技术,研究压入载荷与环形裂纹直径变化的关系。基于均强度理论,推导玻璃局部强度与初始环形裂纹直径之间的关系式,设计通过测量初始环形裂纹直径来反演玻璃强度及残余应力的原位快速测试方法及装置,并进行试验验证。研究结果表明,在达到临界载荷时,玻璃表面产生的初始环形裂纹直径存在一个稳定区,仅当压入载荷递增至临界载荷的120%以上时,初始环形裂纹的圆环内玻璃才破碎开裂,并形成次环形裂纹,次环形裂纹直径随压入载荷增大而减小。初始环形裂纹直径与玻璃开裂时刻的强度相关。

The in-situ and fast characterization testing method of local strength of glass materials was proposed based on the spherical indentation technology,and the relationship between the applied load and diameter of the annular crack was studied.Based on the mean-strength theory,the glass strength and residual stress were calculated by the measured diameter of initial ring crack.Eventually,an effective in-situ and fast test method and the corresponding device for determining the glass strength and residual stress were designed,and the method was also verified by experiments.The results show that the diameter of initial ring crack on the glass surface is unchangeable under the critical load;the glass inside the annular borderline will break and the second ring crack will be formed only when the applied load increases to 120%of the critical load.In addition,the diameter of the secondary ring crack decreases with the increase of the applied load.The initial ring crack diameter implies the glass strength information corresponding to the crack time of the glass.The relationship between the local strength of glass and the diameter of initial ring crack can be deduced.