压剪载荷作用下界面裂纹尖端场的研究

THE STUDY ON INTERFACIAL CRACK-TIP FIELDS UNDER PRESSURE AND SHEAR ~1)

建立了弹性-幂律蠕变双材料界面裂纹准静态扩展的力学模型,求得了裂纹尖端应力、应变和位移场分离变量形式的解及其数值结果;讨论了材料性能参数对裂纹尖端场的影响;计算和分析了界面裂纹的摩擦效应,并且得出了给定条件下裂尖场的轮廓图形.

Three problems are mainly studied about the tip fields of the elastic and power-law creeping bi-material interfacial crack under the loads of pressure and shear in this paper. At first, numerical solutions for the asymptotic crack-tip fields are obtained and analyzed on the basis of the mechanical model established for the quasi-static growth of interfacial crack. The influences of bi-material parameters on the tip-fields are discussed, according to which we find that the ratio of bi-material rigidities is the decisive factor to affect the strength of crack-tip fields. Secondly, the frictional effects of crack-faces are specially calculated and analyzed in detail, and a suggestion is made that interfacial friction must be taken into consideration for engineering structures. It is realized that the shear is the main load maintaining the growth of the interfacial crack loaded under pressure and shear. Thirdly, under the assumption that the crack-tip field is surrounded by elastic field and the effective stresses of the two fields on their boundary are equal, the scale and approximate contour of the tip-field are provided.