I've applied a force and I've experienced a deformation.

我施加一个外力就能观察到形变
I've applied a force and the material has deformed.

我施加一个外力材料就会有形变
I'm going to quantify that, and I can quantify that

我要将其量化本例中我可以相当轻松地
fairly easily because I chose a simple material

进行量化因为我选了一种简单的材料
that had a constant cross-sectional area from the top to the bottom.

从顶端到底部其横截面积都是固定不变的
I'm going to assume that that cross-sectional area doesn't change

假设它发生形变时横截面积不变
when it deforms, but I hang the weight on it and the length increases.

但我挂上砝码时其长度增加了
The length is now L + ΔL.

现长度就是 "L + ΔL"
I can quantify the deformation here by

我在这里就可以通过定义
defining a property called strain.

一个叫做应变的属性来对形变进行量化
The strain is just the change in length divided by the total length.

应变就是变化长度除以总长度所得数值
Now, important

重要的是