The Effect Of Residual Stress On The Performance And Reliability Of The Component Being Engineered

This report will cover the two most used methods of experimental stress analysis; electronic resistance strain gauge and digital image correlation and their relevance in the aerospace industry. Background information, methods of preparation and operation and ways to obtain accurate results will be covered throughout the report.

The tensile testing was done on the three composite specimens (90°, and two 45°) were completed with a servo-hydraulic load frame with a wedge. The one in the lab was the MTS 647 hydraulic wedge grip and an 810 material test system. The specimens had strain gages with a Wheatstone bridge to collect data such as time, distance, load, axial strain, and transverse strain. From the strain gages, evidence can support how and when the specimen material failed under the stress being applied to it. The test was run for three times on three different specimens. The first specimen that was tested in the hydraulic load was the 0°/90° specimen, which is made of carbon and epoxy laminate composite.

However, the absence of plastic deformation does not mean that composites are brittle materials like monolithic ceramics. The heterogeneous nature of composites result in complex failure mechanisms which impart toughness. Fiber-reinforced materials have been found to produce durable, reliable structural components in countless applications. The unique characteristic of composite materials, especially anisotropy, require the use of special design

Stress has been studied by psychologists throughout history and although, evolutionary wise, it is an extremely vital reaction to situations- today, in our society, many situations that evoke the stress reaction can cause unnecessary side effects. Therefore, many psychologists have developed theories and methods to explain and help with stress.

In recent years, both anthropologists and archaeologists have become much aware of the potential importance of the inner workings of human remains than just the anatomical study. Thus, the specialty of bioarcheologists is to focus on nutritional inference, enamel hypoplasia, enthuses, dietary reconstruction, paledemography, demographic analysis, but most importantly, the effects of mechanical stress and indicators on human remains. Mechanical stress is converted to a series of biochemical reactions, and finally activates osteoclasts and osteoblasts to cause bone resorption and formation.

We used this equation along with the force and displacement data to determine the normal stress of the rod when it was axially loaded. P is the applied load and A is the cross sectional area of our sample.

alter the shape of a loaded member and explain the possible effect of excessive stress on a structural member. Annotated sketches are essential.

The corresponding internal forces and displacements are determined using linear elastic analysis. The advantage of these linear dynamic procedures with respect to linear static procedures is that higher modes can be considered. However, they are based on linear elastic response and hence the applicability

The failure compressive load was recorded for each specimen, and the corresponding tensile strength was calculated.

In the classical analysis methods of plane structures, the axial and flexural rigidities are assumed to be constants. However, such ideal conditions are unrealistic because the material behavior is actually nonlinear. The axial and flexural rigidities certainly decrease with the increasing internal forces. The structure geometry is continuously changing with the varying applied forces too .Therefore, developing a step-by-step nonlinear analysis method to investigate such real situations up to failure is

We would like to express our special thanks of gratitude to our lecturer Mrs Aditi, who gave us the valuable guidance for this assignment.

From preliminary design results, stress distribution in the turbine disc obtained using analytical method. This result has to be correlated with the Ansys results. Ansys is a comprehensive FEA analysis tool for structural including linear and non-linear studies. In addition, Ansys Mechanical offers coupled physical capabilities involving thermal- structural and thermal- electric analysis etc.

I express my gratitude and deep regards to my teacher for the subject Mr. Manwendra Kumar Tiwari for giving me such a challenging topic and also for his exemplary guidance, monitoring and constant encouragement throughout the course of this thesis.

(c) Tensile stress : Recommended maximum tensile stress shall not be below 5625Kg/cm2 (80,000 psi.)

There are no words to describe gratitude and thanks to my parents who send me for higher