Truss Analysis is one of the most important topics in Statics, which is the first introductory in structural engineering curriculums. Trusses are structures that are widely used in civil engineering applications, such as bridges, steel buildings and roof structures. Trusses also appear in many mechanical and aerospace structures such as cranes, space structures, offshore platforms, and so on.
What is a Truss?
A truss is a structure usually consisting of straight members that are connected to each other at the two ends of each member. All members of a truss structure are connected together with pin joints, such that for the purpose of the design of these structures we assume the joints cannot carry or resist any moments. All external loads acting on a truss are assumed to be acting only at the joints, and therefore, all members of a truss are two-force members.
Why Must We Learn Truss Analysis?
First of all, if we plan to design and build a truss structure, such as a roof structure for carrying external loads, we need to find out how much load is carried by each member of the truss. Secondly, in the case of an existing truss structure, we may need to replace one or a few members. In this case, we need to find the internal forces carried by those few members within the truss structure. In both instances, the objective is to figure out and decide whether the members can sustain the forces or not and what size members and what type of cross sections are required.
Types of Truss Analysis
There are two major methods of analysis for finding the internal forces in members of a truss; the Method of Joints, which is typically used for the case of creating a truss to handle external loads, and the Method of Sections, which is normally used when dealing modifying the internal members of an existing truss. Both of these methods are based on the assumption that when a structure is in equilibrium, all pieces of the structure are also in equilibrium.
In this course, I will present a thorough overview of truss structures in the context of static analysis of structures. I will provide you with an easy-to-follow, 7-step process for the Method of Joints and the Method of Sections. Each of the 7 steps are clearly demonstrated in the presentation and sample problems, which I will walk through.</p> Updated on 19 April, 2018