Influence of Member Length Imperfection on the Capacity of Spatial Structures

Introduction: Load bearing capacity of Double Layer Grid Spatial Trusses (DLGST) majorly depend on the structures' imperfections. It is important to analyze the systems with consideration of the influences of uncertainties to ensure the safety of DLGST. Methods: The variation of imperfect members’ positions and initial size of length imperfections (being longer or shorter than the ideal size) were selected as the parameters of the current research. Member length imperfections for both long and short members were randomly taken into account according to the randomly generated numbers. These random numbers were generated using a normal distribution. Results and Conclusion: The effect of imperfection is investigated by repeating the analyses simulations on structures with a stochastic dispersion of the imperfect member position and initial length imperfection. It has been demonstrated that the length imperfections might significantly decrease safety of the structure and also shown that the position of imperfect members has effect on the structural performance.