Numerical Investigation of Deflection Prediction of Cold Formed C- Section Roof Purlins

This paper aims to develop equations to ease the calculation of the deformation of C-shaped purlins loaded with live, dead and wind loads. A theoretical research model is created to simulate the behavior of part of a roof steel structure. The model is loaded after connecting its parts with connections similar to that in a steel roof, and the results are extracted using the finite element method (FEM). These results are then used in statistical equations to develop new equations that calculate the values of deformation for the C-shaped sections; the values of vertical, horizontal and rotational displacement are calculated [1], and the results are compared to those in reality. One equation is developed to calculate the value of the horizontal displacement with a total number of specimens of 1055, all of different dimensions, with a degree of confidence of 92%. The specimens are then increased to 2016 specimens with different dimensions, and 3 detailed equations are developed each for a different type of displacement; horizontal, vertical and rotational, with a degree of confidence of 95%. A detailed explanation is provided for how to calculate the deformation in the purlins and how to obtain its value statistically for each different type of displacement, with high accuracy, enabling it to be used in the stage of preliminary design