瓷修复体界面断裂行为的模拟实验研究

Simulated Experimental Study on Interfacial Fracture Behaviors of Porcelain-Fused-to-Metal Restoration

本文利用云纹干涉法和云纹干涉一有限元混合法,对瓷修复体的模拟双材料模型界面断裂问题进行了实验研究。用云纹干涉和数字错位云纹干涉法测量带边裂纹的双材料四点简支梁在剪切作用下界面表面的剪应变分布及界面两侧局部表面的位移场,实验表明,由于界面两侧材料力学性质不同,表现出界面剪切断裂问题的非称性和裂尖附近复合型断裂的特点;用云纹干涉法和有限元法相结合的混合法对粘接界面角点应力奇异性进行研究,并对角点附近应力应变场作了分析,得到了应力奇异指数与边界楔角、载荷的关系,证明了用界面应力强度因子K_f来描述界面端部区域应力分布的公式,并得到了双材料界面端部区域的应力应变分布悄况。本文的实验结果为进一步研究日腔金瓷修复体界面的优化设计提供了基础,同时也说明云纹干涉法对于双材料界面断裂行为的研究是有效的。

The moire interferometry method and moire interferometry-finite element analysis hybrid method have been applied to study interface fracture behaviors of bimaterial specimen which is simulated to porcelain-Fused-to Metal (PFM) restoration. The moire interferometry and digital shearing moire interferometry are used to investigate the interface shear behavior of four-point shearing beam of bimaterial specimen with edge crack in the interface. The shear strain distribution along the interface and the u and v displacement field adjacent to the interface are obtained. The experimental data revealed that the stress state was different, and the fracture parameters were complex due to the interface bimaterial with different mechanical properites. By using hybrid method of moire interferometry with finite element analysis, corner stress singularity and corner stress distribution of a bimaterial specimen are studied respectively. The relationship between the stress singularity exponent and the wedge angle and load valve has been a-chieved. The state of stress and strain around the bimaterial interface end area is obtained. And based on stress, the corner stress intensity Kf, is also obtained. These results provide date for the optimized design of clinician PFM prosthesis. The experimental analysis methods have been used in this study are effectively.