Slide 1

COMPUTERIZED METHODS IN THE ANALYSIS OF PLANE TRUSSES

SANNI OLANREWAJU

MENTOR: PROF. R. NIYAZOV

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Outline

• What is a truss?
• Types of trusses
• Objective
• Equipment
• Methods of analyzing a truss
• Sample calculation
• Summary

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WHAT IS A TRUSS?

• Trusses are a major type of structure consisting of straight members
• We assume truss members are pin-connected at their ends by frictionless pins
• Loads are applied only at the joints

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TYPES OF TRUSSES
(example of a truss)

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(example of a truss)

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OBJECTIVE:

The goal of this project is to analyze the forces in a Bridge Truss.
After performing this experiment and analyzing the data we will be able to:

• Determine the stress and strain exerted in each individual member;
• Get hands-on experience in using the methods of section and joints;
• Test experimentally the conclusions regarding compressed and extended members of a truss.

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EQUIPMENT NEEDED:

• STR-8– Pin Joined Framework
• STR-1A– Digital Force Display
• STR-2000– Automatic Data Acquisition Unit
• STR-8A– Structure Load Cell
• Computer with TQ Structure Computer Software and the Dougle Key

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(example of equipment)

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METHOD OF JOINTS

The main idea of this method is to capitalize on the concept that , When an entire truss is in equilibrium, each of its parts (members, joints, pins) will also be in equilibrium.

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METHOD OF SECTIONS

• The advantage of the method of sections is that it allows the analysis of the internal forces acting in any member of the truss (not a joint).
• A joint-by-joint analysis is not required in this method.
• The basic steps of the method of sections are as follows:
• Examine the structure for stability and statical determinacy.
• If the truss is not of the cantilever type, calculate the reactions at the support of the truss.
• Draw an imaginary plane through the whole truss, bisecting the truss into two sections. The plane must intersect no more than three members, including the member whose internal force is being analyzed.

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(examples)

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RESULTS

(table)

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Table 2: Theoretical Member Strains for the Truss (by method of Joints or Section)

(table)

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Table 3: Comparison of Experimental and Theoretical Forces

(table)

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• Trusses consist of pin-jointed members that undergo stress and strain when load is applied
• There are mainly two methods in the analyses of trusses, which are:
• Methods of joints
• Methods of sections

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ACKNOWLEDGEMENTS

• My mentor Prof. Niyazov for his encouragement and assistance.
• Prof. van Loon, the director of the C-STEP program and the C-STEP mentors for their support and guidance.