Arch height refers to the vertical distance between the main spring leaf and the center line of the spring eye in the leaf spring. In the calculation of solid boundary line of surface, the arch height of a point reflects the bending degree and convexity of the boundary line of that point.
Arc is a Chinese word, and the pinyin is yuán hú. The part between any two points on a circle is called an arc. Maths is taught in junior high school and senior high school. Two endpoints of any diameter of a circle divide the circle into two arcs. Those larger than a semicircle are called optimal arcs, and those smaller than a semicircle are called suboptimal arcs.