New transverse extension modes for the constrained finite strip analysis of thin-walled members

In this paper a new way to define transverse extension modes is introduced in the context of modal analysis of thin-walled members. The new primary transverse extension modes are inspired by the strain distributions of global and distortional modes. The new modes are employed here in the constrained finite strip method. The new modes require some change in the interpolation functions of the semianalytical finite strip method, which change is briefly discussed. The practical advantage of the proposed new transverse extension modes is that the artificial stiffness increase, which is characteristics to constrained analyses, can be compensated by the consideration of the relevant new transverse extension mode(s), as illustrated by numerous proof-of-concept examples in the paper.