Strain Gauge Material Properties

Strain in the material is a critical factor determining damage effect and durability.

Strain gauge material properties.

As the object is deformed the foil is. The sensitivity of metal strain gauges can be 10 6 strain. Mechanical properties are essential in describing the behaviour of a material when a load is applied. One of the most popular materials used for the strain gauges is the.

The types of construction for these include thin film foil and semiconductor strain gauges. Although semiconductor materials exhibit substantial nonlinear behavior and are temperature sensitive. A strain gauge also spelled strain gage is a device used to measure strain on an object. 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.

Determination of material properties of standardized test samples. Materials used for the strain gauges. 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. 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. Simmons and arthur c. 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. Metal strain gauges have a gauge factor of about 2.

Select constantan advance copel alloy wire if. Invented by edward e. Constantan in this form is very ductile. Many tests such as tension compression impact bending shear torsion and hardness tests are developed in order to observe the response of a material to an applied external force these properties are important in order for engineering designers to select appropriate materials for.

And in gauge lengths of 0 125 inches 3 2 mm and longer can be strained to 20. Applications are mainly static or quasi static strains. Determination of durability parameters of components structures in the test bench or in the field. The material construction of the wire directly affects the sensitivity of the strain gage.

Ruge in 1938 the most common type of strain gauge consists of an insulating flexible backing which supports a metallic foil pattern. Further discussion on sensitivity can be found in the strain gage sensitivity page. There are many different test standards for composite materials that involve the use of strain. Because of this.

Specialized semiconductor strain gauges based on silicon have gauge factors of 50 to 200 but these devices are nonlinear making them more difficult. The metals can be easily cut into the zigzag foils for the formation of the strain gauges. Variation in expansion coefficients between the gage and base materials may cause dimensional changes in the sensor element.