**Branch :**Civil Engineering

**Subject :**Structural Analysis -2

## Introduction of Plane Trusses

Introduction

Trusses are assemblies of members whose actions can be linked directly to that of the

simple spring studied already:

There is one main difference, however: truss members may be oriented at any angle in the xy coordinate system (Cartesian) plane:

Thus we must account for the coordinate transformations from the local member axis system to the global axis system.

**Matlab Program – Data Preparation**

In the following sections we will put the final pieces of code together for our Truss Analysis Program. At this point we must identify what information is required as input to the program, and in what format it will be delivered. The node data is stored in a matrix nData. Each node of the truss is represented by a row of data. In the row, we put the following information in consecutive order in columns:

**1. x-coordinate;**

2. y-coordinate;

3. x-load: 0 or the value of load;

**4. y-load: 0 or the value of load;**

**5. x-restraint: **0 if unrestrained, any other number if restrained;

**6. y-restraint:** 0 if unrestrained, any other number if restrained.

The element data is stored in a matrix called eData. Each element has a row of data and for each element the information stored in the columns in order is:

**1. i-Node number**: the node number at the start of the element;

**2. j-Node number: **the other node the element connects to;

**3. E:** the Modulus of Elasticity of the element material;

**4. A: **the element area;