General Equipment | Mechanical & Manufacturing Engineering

Stress Testing Kit

A predominant factor contributing to the structural failure of machine parts, pressure vessels, framed structures, etc., may be the residual “locked-in” stresses that exist in the object prior to its being put into service.These residual stresses are usually introduced during manufacturing, and are caused by processes such as casting, welding, machining, heat treating, molding, etc. Residual stress cannot be detected or evaluated by conventional surface measurement techniques, since the strain sensor (strain gage, photoelastic coating, etc.) can only respond to strain changes that occur after the sensor is installed.

The most widely used practical technique for measuring residual stresses is the hole-drilling strain gage method described in ASTM Standard E837. With this method, a specially configured electrical resistance strain gage rosette is bonded to the surface of the test object, and a small shallow hole is drilled through the center of the rosette. The local changes in strain due to introduction of the hole are measured, and the relaxed residual stresses are computed from these measurements.

Digital Strain Indicator and Switch and Balance Unit

Room No: SB39

Model No: P - 3500 / SB10

 

Equipment Specifications & Manuals