Non- linearity behaviour

Report content Introduction Two- dimensional stress and strain Multi- channel strain measurement Non- linear behavior of thin plates Objectives Theory and baackground Two- dimensional state of stress and strain Resistance strain gauges, gauge rosettes and strain measurement circuits Linearity of material behavior and structural behavior Equipment Arrangement of strain gauge rosettes on the plate Plate loading rig Procedures Loading Unloading Results Discussion Conclusion References

Introduction

Two dimensional stress and strain

Stress and strain are one of the most fundamental yet important concepts in the field of engineering. Two-dimensional stress and strain are normally found in a structure where one of the dimensions is very small as compared to the others, such as the thin plate we will be using in our experiment.

Multi- channel strain measurement

In our study, we are often interested in the amount of stresses resulted from the load applied, but there is no direct way of obtaining it. However, the strains resulted can be measured by using the resistance strain gauge and by applying the generalized Hooke’s Law, we can find out the corresponding stresses.

One thing to take note is that the special circuits used for taking static strain measurements is very sensitive, therefore extra precautions are required to obtain accurate and reliable results.

Moreover, two- dimensional strains are usually not uniform throughout the surface when load is applied. Hence, we will be using multi- channel strain measurements to find out how the strains changes at different places of the body.

Non- linear behavior of thin plates

We can see that in many mechanical and structural systems, thin plate components are often laterally loaded. So, it is very important to understand that even when the materials remain linearly elastic while the thin plates are under lateral loads, it can still display an unusual non-