Structural engineering includes designing and analysing plane trusses, which is one of the most basic but effective skills. Working on a bridge, roof trusses, or industrial frame, knowing the calculations of the forces in the truss members is essential in providing safety, stability and economical concerns in a design.
We are going to take you through the entire plane truss analysis process in this article, which will involve methods, assumptions, formulas, and tips for doing it. At the end, you will have no problems computing the member forces both analytically and through Excel-based means.
What Is a Plane Truss?
A plane truss is a structure that consists of two-dimensional straight members fitted at their ends using pinned joints. The primary role of a truss is to assist in the transfer of loads by compression and tension, but not bending.
Typical examples include:
- Roof trusses
- Bridge trusses
- Transmission towers
- Crane structures
The trusses within a plane are positioned in a single plane and are connected at triangular-shaped joints, which increase geometric stability.
Simple Truss Analysis Assumptions
The main assumptions that should be kept in mind before doing any calculation are:
- Frictionless pins connect all the members.
- The loads and reactions are realised only at the joints.
- The members are two-force members (only tension or compression is applied).
- The weight of the members is not significant (unless stated otherwise).
These assumptions make the analysis simple since you can use the equilibrium equations of a static analysis to ascertain the forces of the members.
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