Behavioural Study of Truss Bridge using Isogrid Members

Abstract

The search for lightweight and highly efficient structural components is a continuing process. Reducing the structural weight and improving the load carrying capabilities of these structures will allow designers to append additional capabilities while reducing cost. Isogrid is a lattice of stiffened ribs forming an array of contiguous equilateral triangles. This rib pattern forms triangular trusses by maintaining isotropic property. Ribs when arranged in 60? pattern are known as Isogrid. The highly redundant nature of Isogrid stiffening concept provides high efficiency distributing loads and is less susceptible to impact damage, delamination, and crack propagation. Isogrid structure is typically found in stiffness critical components that resist buckling. The behavior and performance of Isogrid deck slab in a Bridge supported by the truss girders is studied.  Isogrid is modeled, analyzed and designed using commercial Finite Element (FE) software. In the present work, a truss bridge is designed for a span of 10.305 m. The bridge is designed using three different kinds of deck configuration, rectangular section without skin, inverted T section with skin, and I section with skin.  Commercial FE software is used for computing deflections and stresses. It is found that the deck profile of I section with skin is more preferable than other configurations for Truss Bridge.