Abstract
The buckling stress relational formula under the combined stress of compression and shear is derived concerning a rectangle thin shell which constitutes the frame structure of a car body. The approximate buckling stress relational formula is shown by deriving the exact formula of the combined buckling stress based on the energy method, and by simplifying that formula. The accuracy of this approximate formula is confirmed as compared with the conventional relational formula. As the result, it is found that the exact solution can be expressed accurately by the derived formula here than the conventional formula.
