用有限元法研究短纤维／橡胶复合材料内应力传递

采用有限元法对短纤维／橡胶复全材料内应力传递和分配规律进行了初步探讨。结果表明：纤维末端的界面剪切应力和纤维中部的拉伸应力均最大，纤维末端仍传递一定的拉伸应力；纤维体积分数越大，纤维末端端应力集中越严重；纤维长径比越大，纤维上的最大拉伸 力也越大，但增幅越于平缓；纤维模量增加，纤维上的拉伸应力集中也增加，但增减缓，基南模量增加，界面剪切应力集中和纤维拉伸应力集中均下降，但剪切应力和拉伸应力的红色     

蓄热室底板的结构构造和应力分析

蓄热室是浮法玻璃熔窑结构的重要组成部分.设计的蓄热室底板既要有耐高温能力,又要有必要的承载力和耐久性.本文对蓄热室底板的结构构造和受力状态做了详细的分析.     

FLOW OF VISCOPLASTIC FLUIDS ON AN INCLINED PLANE: EVALUATION OF YIELD STRESS

Within the general category of so called generalized Newtonian fluids, there exists a class of materials which do not deform until the applied shear stress exceeds a critical value called yield stress. Conversely, such a material behaves like a solid as long as the shear stress is less than the yield stress. This class of materials is called viscoplastic fluids. The question whether the true yield stress exists or not is indeed far from settled (1), but the notion of a yield stress has proved to be quite useful in practice in describing the steady shear rheological behaviour of a range of materials especially of particulate suspensions. Consequently, yield stress appears as a parameter in all constitutive relations (which purport to describe the steady shear behaviour of viscoplastic materials), and its evaluation is important before an engineering flow problem can be solved. Conversely, there are some simple hydrodynamic situations which allow the value of the yield stress to be extracted from macroscopic quantities such as flow rate-pressure drop data. In this paper, we examine this possibility using gravity driven flow of a viscoplastic material on an inclined plane.