关键词: 计算接触力学, 有限元, 颗粒材料, 橡皮膜嵌入, 三轴试验

Abstract: Rubber membrane penetration can cause significant errors in volumetric deformation measurement in the triaxial test of coarse-grained materials. Considering the characteristics of particle contact, this paper presents an efficient algorithm for detecting particle contact state based on the particle surface that is reconstructed using the Nagata patch method. We simulate particle-membrane contact using a dual mortar method and a large geometric deformation algorithm, and modify the particle-membrane film distance based on the particle surface reconstruction. Hence, refined simulation of particle-membrane contact is realized and the penetration process of a flexible rubber membrane can be calculated. Simulations are carried out to study the membrane penetration processes in Kramer’s steel ball test, coarse-grained triaxial test, and standard coarse sand triaxial test. The calculation results are consistent with the general rules and agree well with the test results, indicating that our method is applicable to simulation and analysis of the membrane penetration process of coarse-grained particles.

Key words: computational contact mechanics, the finite element method, particle material, membrane penetration, triaxial test