On the shortcomings of strain electrical measurement method

The disadvantage of strain electrical measurement method is: 1. The difficulty of electrode installation; 2. Interface effect between electrode and material; 3. Electrode shedding and stability; 4. Only surface measurement

The basic principle of strain electrical measurement is to measure the linear strain on the surface of the component with a resistance strain gauge, and then determine the stress state on the surface of the component according to the strain-stress relationship.

This method is to stick a resistance strain gauge on the surface of the tested component. When the component is deformed, the resistance value of the resistance strain gauge will change accordingly, and then the resistance change will be converted into a voltage (or current) change by the resistance strain gauge, and then converted into a strain value or output a voltage (or current) signal proportional to it. The measured strain or stress can be obtained by recording with a recorder.

1. electrode installation difficulty:

The strain electrical measurement method needs to install electrodes on the surface of materials, which requires certain technical and operational experience. The installation of electrodes may damage the surface of materials and affect the mechanical properties of materials.

2. Interface effect between electrode and material:

In strain electrical measurement, the interface effect between electrode and material may affect the accuracy of measurement results, leading to local concentration or diffusion of strain, thus affecting the uniformity and accuracy of strain.

3. Electrode shedding and stability:

The electrode may fall off or loosen during the stress process, resulting in distortion or interruption of the measurement signal, and the stability of the electrode may bring challenges to the measurement of long-term or complex strain state.

4. Only surface measurement:

Electrical strain measurement method is mainly suitable for measuring surface strain, but it has certain restrictions on the measurement of internal or three-dimensional strain of materials, which may limit the comprehensive understanding and analysis of strain distribution in materials.

Strain electrical measurement is one of the commonly used methods in material mechanics testing, which can be used to measure the relationship between strain and stress of materials. Although strain electrical measurement has many advantages.

5. Advantages of electrical measurement method

The measurement sensitivity and accuracy are high: the minimum strain is 1με(με- microstrain, 1με= 10ε). The error of static measurement at room temperature is generally1~ 3%; In dynamic measurement, the error is in the range of 3 ~ 5%.