Pipe punching machine When a part works under rated working conditions, it is considered that the part meets the strength requirements when it does not have any form of damage or residual deformation beyond the allowable limit, and can ensure the normal operation and work of the machine. Zinc steel guardrail punching machine Insufficient strength is the direct cause of fracture or excessive residual deformation of parts in operation.

The strength of parts is divided into volume strength and surface contact strength. For example, pipes Punching machine If the stress of a part under load is within a large volume, the strength of the part under this stress state is called volume strength (strength for short). If two parts change from point contact or line contact to small surface contact before and after being loaded, and their surfaces produce large local stress (called contact stress), then the strength of the parts is called surface contact strength (called contact strength for short).

In design, most important parts are checked by strength conditions (relevant strength theory in engineering mechanics), except some parts with small force or complex shape that cannot be calculated are determined by experience and experiments. If the strength of the parts is not enough, the overall fracture, surface contact fatigue or plastic deformation and other failures will occur and the working ability will be lost, so the strength requirements must be met when designing the parts.