厚壁胞体多孔结构接触强度研究

STUDY ON CONTACT STRENGTH OF THICK-WALLED CELLULAR STRUCTURES

选用H59黄铜为材料,制备了含圆形单孔、双孔、三孔以及四孔的圆柱体试样,采用型号为YE-600的液压式压力试验机对试样进行压缩试验,探讨了布孔方式对厚壁胞体多孔结构接触强度的影响;并用有限元法探讨了多孔结构的破坏机理.结果表明:双孔材料水平布孔方式优于垂直布孔方式;三孔材料斜正三角形布孔方式优于正三角形布孔方式;四孔材料正方形布孔方式优于菱形布孔方式;微孔分布半径的增大和微孔个数的增加均有助于提高厚壁胞体多孔结构的接触强度;裂纹萌生于微孔边缘且离初始接触点最近的地方,它由最大拉伸主应力引起并沿着微孔拉应力集中区进行扩展.

Materials of H59 brass has been chosen for the preparation of cylindrical specimens which contain one pore,two pores,three pores and four pores,and YE-600 hydraulic pressure testing machine has been used for compression tests on these specimens.The effects of pore distribution on contact strength of thick-walled cellular structures have been discussed,and the damage mechanism of cellular structures has been explored by finite element method.The results show that：the level distribution approach of two pores is superior to the vertical approach;oblique equilateral triangle distribution approach of three pores is better than the equilateral triangle approach;square distribution approach of four pores is superior to the diamond approach;the increasing of pore distribution radius and the number of pores will improve the contact strength of thick-walled cellular structures;cracks generated in the edge of pore which is the nearest away from the initial point of contact;the cracks were caused by the largest principal stretching stress and expanded along the zone of pores stress concentration.