Member Buckling with Joint Instability - Design Application

Compression member buckling in association with joint instability was observed in several truss and model tests, involving certain types of prefabricated systems. It was also evident in a recent collapse. The paper presents an analytical procedure for evaluating the influence of the connection stiffness on the member elastic buckling load. The proposed model, which is suitable for implementation with the aid of spreadsheet calculations, is intended as an indication of the sensitivity of the system to joint instability and the need for rigorous stability and non-linear analysis. Some examples are presented, comparing results of the proposed method with analytical and numerical computations and with test results.