Local and distortional buckling of thin-walled laminated lipped channel columns

The great versatility in manufacturing and handling, as well as the mechanical capacity in structural applications, lead to the increase in the application of composites in various engineering applications, including aerospace industry, automotive industry, renewable energy, and civil construction. Due to the high strength and stiffness of fiber reinforced composites, they are mostly used to manufacture thin-walled structural components. It is already known that buckling plays a significant role in the design of thin-walled structures subjected to compressive loads, such that failure can occur with stresses much lower than the material mechanical strength. Thus, the design of many structural components is carried out considering constraints related to stability along with traditional criteria of strength and stiffness. This work focus on the stability analysis of laminated lipped channel columns. These columns present three main buckling modes: local, distortional, and global. It is important to note that the buckling loads of laminated open-section columns with arbitrary layup can be accurately computed using the Finite Element Method. However, the application of this approach to trace the signature curve of composite columns with channel sections is cumbersome and presents a high computational cost. Therefore, this work presents a simple, efficient, and accurate methodology to evaluate the local and distortional buckling load of laminated channel columns applying the Rayleigh-Ritz method. The accuracy of the proposed approach is assessed comparing the results obtained using the Finite Strip Method, Finite Element Method, and experimental data available in the literature.