应变花的图解法 在一点K的任意三个方向(Ⅰ、Ⅱ、Ⅲ)上测量线应变时,我们把这三个方向组成的图形叫做“应变花”(图1),夹角α、β是已知的,三个方向上的线应变e_1、e_2、e_3可以测得。通常采用图解的方法由这五个已知数求出主方向(由φ角决定,假定图中所示位置的φ角为正值)和主应变ε_1、ε_(20) Strain Gauge Method When the linear strain is measured in any of three directions (I, II, III) of a point K, the pattern consisting of these three directions is called “strained flower” (Figure 1) and the included angles α, β Is known, the line strain e_1, e_2, e_3 in three directions can be measured. The principal direction (determined by the angle φ, assuming that the φ angle at the position shown in the figure is a positive value) and the principal strains ε_1, ε_ (20)