There are many experiments of quasi-static strength in vehicle development, such as roof intrusion, seat belt anchor strength, etc. Recently, explicit dynamic codes are used for quasi-static large deformation analysis. In this paper three explicit dynamic methods are applied to (1) panel strength analysis with large deformation and (2) buckling analysis of shallow arch and (3) collapsed analysis of spot welded thin-walled hat shape columns subjected to axial crushing. The system damping method is the quasi-static analysis that in the dynamic FEM equation we use large damping vector, which is obtained by multiplying the first eiginvalue to mass matrix. and 2nd is dynamic relaxation method, and 3rd is mass-scaling method. First, we point out that the system damping method is superior to conventional static FEM from the viewpoint of accuracy and efficiency only with the eigenvalue in which the eigen mode is similar to the first generated static buckling mode. Second, we point out that the dynamic relaxation method is the best analytical method for the (1) problem and for the (2) problem, system damping method is the best one and mass-scaling method is the best one for the (3) problem.