Strain Gauge Material Properties

Specialized semiconductor strain gauges based on silicon have gauge factors of 50 to 200 but these devices are nonlinear making them more difficult.

Strain gauge material properties.

A strain gauge also spelled strain gage is a device used to measure strain on an object. A conductive material is bonded to a thin backing. Thus a strain of 0 1 will cause a 0 24 ω change in a 120 ω strain gauge. Invented by edward e.

Ruge in 1938 the most common type of strain gauge consists of an insulating flexible backing which supports a metallic foil pattern. Metal strain gauges have a gauge factor of about 2. As the object is deformed the foil is. The material construction of the wire directly affects the sensitivity of the strain gage.

There are many different test standards for composite materials that involve the use of strain. The types of construction for these include thin film foil and semiconductor strain gauges. Materials used for the strain gauges. Applications are mainly static or quasi static strains.

Determination of material properties of standardized test samples. Further discussion on sensitivity can be found in the strain gage sensitivity page. The sensitivity of metal strain gauges can be 10 6 strain. Although semiconductor materials exhibit substantial nonlinear behavior and are temperature sensitive.

Variation in expansion coefficients between the gage and base materials may cause dimensional changes in the sensor element. 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.

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. One of the most popular materials used for the strain gauges is the. The gauge is attached to the object by a suitable adhesive such as cyanoacrylate. The metals can be easily cut into the zigzag foils for the formation of the strain gauges.

Determination of durability parameters of components structures in the test bench or in the field. Strain gauge sensors use the strain gauge element as the underlying mechanism. 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. Mechanical properties are essential in describing the behaviour of a material when a load is applied.

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