Trusses Offered Within Our Company
Roof Truss
A roof truss is an integral part of framework that supports the weight of a roof. It is made of wood or metal units connected with plates or joints. Trusses distribute the weight evenly, allowing for larger spans without extra support.
Floor Truss
Floor trusses are structural components used to support building flooring systems. They are typically made from wood or metal and consist of interconnected triangular-shaped members. These trusses offer flexible span lengths and enable the integration of mechanical, electrical, and plumbing systems within the floor system
All About Trusses—
A truss is a structural framework composed of interconnected elements at pin joints or nodes. In theory, these joints act as hinges with no rotational resistance. However, practical instances may differ. Trusses are advantageous because their components are predominantly subjected to axial loads, either compression, tension, or no force (referred to as zero-force members). This inherent characteristic makes trusses an efficient structural design. This article explores various types of trusses, their characteristics, approximate analysis methods, and underlying assumptions. For instance, it discusses manual analysis techniques to determine member forces and introduces a truss analysis toolbox for those interested in truss behavior.
Trusses are commonly found in the built environment due to their efficiency in spanning large distances with minimal material usage, making them suitable for roofs and bridges.
Typical Truss Types
Several truss patterns have developed to suit different needs, such as Pratt, Howe, Warren, and Modified Warren trusses. The pattern refers to the arrangement of internal vertical and diagonal members, with the top and bottom horizontal elements known as truss chords or booms.
Pratt truss, proposed by Thomas Pratt in 1844, features vertical and diagonal members forming an 'N' pattern. Diagonal members only experience tensile forces, while vertical members endure compression. This truss is conducive to hand analysis.
Howe truss, proposed by William Howe in 1840, is the upside-down version of the Pratt truss. Vertical members are under tension, and diagonals are under compression. However, the longer diagonals might buckle when facing vertical or gravity loads.
Warren truss, designed by James Warren in 1848, omits internal vertical members, relying on equilateral triangles. The diagonal members alternate between tension and compression, making it economical in terms of material usage.
These truss types emerged during the Railway Mania of the 1840s, marked by intensive railway network development, leading to innovations in bridge design.
Modified Warren truss reintroduces vertical members to reduce the span between nodes in the top (often compression) chord, aiding in cases of compression in horizontal members. It's useful for supporting secondary structures like roof purlins.
Vierendeel Truss
Distinct from common trusses, the Vierendeel truss transmits forces differently. Unlike pin jointed trusses composed of triangles, a Vierendeel truss features rectangular or square openings due to rigidly joined members. This structural design handles axial forces and bending moments, making it stiffer and more substantial, albeit at a higher material cost.
Truss Design
Designing trusses involves relatively straightforward processes. Approximating details can be achieved through basic analysis. Calculating sizes of horizontal members requires determining axial forces at maximum bending points. Internal member sizes are determined by magnitudes of internal forces, often analyzed using methods of joints and sections.