Strain Gauge Material Properties

Determination of durability parameters of components structures in the test bench or in the field.

Strain gauge material properties. The gauge is attached to the object by a suitable adhesive such as cyanoacrylate. As the object is deformed the foil is. In equation 5 13 the metal strain gage behavior is explained by 1 2υ parcel the dimensional effect but to semiconductor strain gages the piezoresistive parcel πe predominates the change in resistivity has a greater effect on the value of the resistance than the change in geometry. Invented by edward e.

One of the most popular materials used for the strain gauges is the. The sensitivity of metal strain gauges can be 10 6 strain. Because of this. Earlier wire types of strain gauges were used commonly which are now being replaced by the metal foil types of gauges as shown in the figure below.

A conductive material is bonded to a thin backing. And in gauge lengths of 0 125 inches 3 2 mm and longer can be strained to 20. Metal strain gauges have a gauge factor of about 2. Ruge in 1938 the most common type of strain gauge consists of an insulating flexible backing which supports a metallic foil pattern.

Select constantan advance copel alloy wire if. Simmons and arthur c. Further discussion on sensitivity can be found in the strain gage sensitivity page. Although semiconductor materials exhibit substantial nonlinear behavior and are temperature sensitive.

There are many different test standards for composite materials that involve the use of strain. Applications are mainly static or quasi static strains. A strain gauge also spelled strain gage is a device used to measure strain on an object. Constantan in this form is very ductile.

Strain gauge sensors use the strain gauge element as the underlying mechanism. The metals can be easily cut into the zigzag foils for the formation of the strain gauges. Strain in the material is a critical factor determining damage effect and durability. Specialized semiconductor strain gauges based on silicon have gauge factors of 50 to 200 but these devices are nonlinear making them more difficult.

The material construction of the wire directly affects the sensitivity of the strain gage. It should be borne in mind however that under high cyclic strains the p alloy will exhibit some permanent resistivity change with each cycle and cause a corresponding zero shift in the strain gauge. Materials used for the strain gauges. Determination of material properties of standardized test samples.

Temperature can influence not only the properties of a strain gage element but also can amend the properties of the base material to which the strain gage is attached. The types of construction for these include thin film foil and semiconductor strain gauges. Variation in expansion coefficients between the gage and base materials may cause dimensional changes in the sensor element.