Abstract
This paper measures and calculates the stresses of the two leaves spring assembly of a car by using strain gauge technique. The experiment discovers that under various restrained degree, the stress distributions are similar and the stress values vary little about 5-8% out of U-bolt, and the trends of stress distribution are similar and the stress values vary more between the U-bolt. With the decrease of restrained degree, the stress values increase rapidly, and when the restrained degrees arrive at a limit value, the stress is more than normal permissible stress. In the structure design of a few leaves spring, ensuring stress and its varied value between U-bolts small is the main duty for improving the life of a few leaves spring.