What is the mechanical changes before and after strengthen?

The original structure already had certain stress and strain before reinforcement and reconstruction. In the later stage, the stress and strain of the new part of the component is generally lower than the original structure, which has great influence on the mechanical properties of the structure.

The new and old parts of the structure are not formed at once. When they are loaded together, there are problems of coordinated deformation and collaborative work, which also have a great influence on the structural mechanical behavior after reinforcement.

Inappropriate reinforcement and modification schemes may have negative effects on the original structure, such as increasing the base stress, changing the structure quality or stiffness distribution, and so on.