延安大学：《结构力学 Structural Mechanics》课程教学资源（模拟考试）第01套（答案）

The logical extension of discrete mass systems is one of an infinite number of masses. In the limit, this is a continuous system. Take the generalized beam-column as a generic representation:

Thus far we have discussed mechanical loading and the stresses and strains caused by that We noted, however, that the environment can have an effect on the behavior of materials and structures. Let's first consider:

Summarizing what we've looked at in elasticity, we have: 15 equations in 15 unknowns 3 equilibrium -6 strains -6 strain-displacement -3 displacements

There are many structural configurations where we do not have to deal with the full 3-D case. First let's consider the models Let's then see under what conditions we can apply them A. Plane Stress

As we've previously noted, we may often want to describe a structure in various axis systems. This involves... Transformations (Axis, Deflection, Stress, Strain, Elasticity Tensors) e.g., loading axes material principal axis Figure 7.1 Unidirectional Composite with Fibers at an Angle

We do not characterize materials by their E mnpq The Emnpa are useful in doing transformations, manipulations, etc. We characterize materials by their \ENGINEERING CONSTANTS\ (or, Elastic Constants)

Sources of Stresses and Strains Depends on type of structure Aircraft

《结构力学》课程授课教案（讲义）第一章 绪论 1.5 小结

《结构力学》课程授课教案（讲义）第一章 绪论 1.4 荷载的分类