轴向加载时的内力.pdf

文档介绍：Stress and Strain due to Axial Loads


CHAPTER 8
STRESS AND STRAIN DUE TO AXIAL LOADS



Internal Force and the Axial Force 轴向加载时的内力
Diagram of an Axially Loaded Member 及轴力图
Using the method of sections and the equations of 应用截面法和平衡方
equilibrium of either part of the member, it is easy to 程,可以很容易发现轴向加
find out that the internal force of an axially loaded 载作用下的构件的内力只
member is axial force only. 有轴力。
It is very often that there are several constant 通常会有多个不变的
external forces act on the member. Therefore, the 外力作用在构件上。因此,
internal force varies along the member’s length. The 轴力沿杆长方向是变化的,
internal force in each segment of the member, between 任意两个外力间的内力应
any two external forces, must then be determined by 由截面法获得,并画轴力
using the method of section. Then the axial force 图。画图之前应首先做符号
diagram of an axially loaded member can be drawn. A 规定。当产生拉力和伸长时
sign convention must be developed first. Both the force 力和位移都为正,反之,负
and displacement are considered to be positive if they 的力和位移分别引起压力
cause tension and elongation, respectively; whereas a 和压缩。
negative force and displacement will cause

compression and contraction, respectively.


Average Normal Stress in an Axially 轴向加载时的平均
Loaded Member 应力
There is only normal stress on the cross-sectional 在轴向加载的构件中
area in an axially loaded member. This normal stress is 只有正应力。由于构件是定
constant