8.0. STRUCTURAL ANALYSIS

Structural analysis is solving the forces of each member in a system. Trusses are used for this objective due to some advantages. But first, what are trusses? A truss is a structure having slender members joined together at their ends. Two kinds of trusses are (a) planar or 2D trusses and (b) spatial or space trusses (3D).

credits to WWW.KENTRUSSES.COM

DESIGN ASSUMPTIONS

To determine the force of each member, there are important assumptions to be considered:

• Truss members are joined by smooth pins
• Loads are applied at the joints.

These assumptions will lead the analysis to a conclusion that each member of the truss acts as a two-force member, and that this force will be acting along the axis of the member. These two kinds of forces are:

• Tensile force
• Compressive force

METHODS OF ANALYSIS

The method of joints. This is a method used when you are to analyze all the member forces in a system. It works on the fact that the whole truss is in equilibrium. The method starts with determining the support reactions of the truss with the applied load. Then internal member forces will be determined by using the equations of equilibrium in each joint.

EXAMPLE 8.0.1. METHOD OF JOINTS OF A SIMPLE TRUSS

EXAMPLE 8.0.2. METHOD OF JOINTS OF A SIMPLE TRUSS

EXAMPLE 8.0.3. METHOD OF JOINTS OF A SIMPLE TRUSS

The method of sections. This is the method used when there are specific members needing analysis for internal forces. After identifying the external support reactions. Method of sections would apply a cutting plane to section the truss into parts making it easier to directly compute for the required member force.

EXAMPLE 8.0.4. METHOD OF JOINTS OF A SIMPLE TRUSS

EXAMPLE 8.0.5. METHOD OF JOINTS OF A SIMPLE TRUSS

EXAMPLE 8.0.6. METHOD OF JOINTS OF A SIMPLE TRUSS