动态非协调接触状态的实验表征方法研究

In this project, a contact state characterization method is proposed for the dynamic non-conforming contact problem. Basing on the experimental measured displacement and inverse method, this method can obtained the contact area and contact force indirectly. The basic procedure is as follows: first, the displacement field of the contact member is measured and the contact region is located by using the speckle image sequence captured before and after the contact. Second, the relationship between the contact area, the contact force and the displacement are determined according to an established contact model. Last, the parameters including the contact area and contact force are inversed by matching the calculated displacement and the measured one. The segmentation-aided digital image correlation technique is developed to acquire the displacement near the contact interface, and an alternating optimization method is proposed to obtain the optimal parameters. The proposed method can characterize the contact state without changing the interface properties, which can provide a new method for the study of the non-conforming contact, the analysis of the contact force and contact area evolution of the structures in the industry.

本项目针对动态非协调接触问题，提出了一种接触状态的实验表征方法。该方法以实验位移场与参数反演方法为基础，能够间接测量接触面积以及接触力分布。基本思路是：首先基于接触前后的散斑图像序列测量接触体位移场，并定位接触区域；其次，建立接触模型，得到接触面积、接触力与位移场之间的定量关系；最后对模型计算得到的位移场与实验测量位移场进行匹配，反演包括接触面积、接触力在内的各个参量。其中，发展分割辅助数字图像相关技术获取接触边界位移场，提出分部优化算法得到各个参量的最优解。该方法可以在不改变界面特性的情况下表征接触状态，为研究物体间的非协调接触行为、分析工程构件间的接触力以及接触面演化等提供了新的实验测试方法。

本项目针对动态非协调接触问题展开接触状态的实验表征方法研究，期间所取得的主要进展及成果包括：（1）提出了非协调接触状态表征方法。建立了接触状态与接触附近区域位移的关系，开发位移匹配算法，实现了接触参数的反向表征。（2）提出了接触力表征方法。基于边界元建立接触模型，结合全场位移测试技术与优化算法实现摩擦接触问题中接触力的测量与分析。（3）开发了用于压入现象表征的力学模型以及实验表征方法。提出了半解析接触模型、基于位移匹配的参数反演算法以及基于位移残差的屈服准则。（4）提出了用于接触变形分析的实验测试方法。该方法以分割辅助数字图像相关技术为基础，结合接触理论实现由位移到应变的计算与重建。（5）发展了异常数据去除方法，显著提升由光测位移场到应变场这一过程的计算精度。该项目所发展的接触状态表征方法为工程中广泛存在的接触现象提供了有效的实验研究手段，具有一定的科研与实际应用价值。