Comparative Structural Analysis of Pratt and Warren Truss Bridges under Horizontal Loading

This study presents a comparative investigation of the structural performance of six-span Pratt and four-span Warren steel truss bridges under a concentrated horizontal load of ۲۰۰ kN. Using finite element analysis (FEA), the lateral response, stress distribution, and displacement patterns of both configurations were evaluated. The numerical results indicate that both truss systems exhibit exceptional stiffness and stability under lateral loading, with stress levels well within the elastic range of structural steel, confirming a high safety margin. While the Pratt truss relies on its vertical and diagonal members to resist lateral actions with minimal horizontal drift, the Warren truss demonstrates a robust response through its triangular geometry, which effectively translates the horizontal load into internal axial forces while maintaining vertical stability against secondary rotational effects. The comparison highlights that both configurations are highly efficient in resisting lateral environmental actions, with their respective internal force distribution mechanisms providing distinct advantages in terms of structural stiffness and load redistribution under horizontal service conditions.

کلیدواژه ها:

Pratt ، Warren steel truss ، axial forces