Calculate Tensile Stress with Strain Gauge

In summary, a strain gauge is a type of sensor that measures changes in resistance to determine the amount of strain and tensile stress on a material. This is done by attaching the gauge to the material and measuring the change in resistance as the material is stretched or compressed. The formula for calculating tensile stress with a strain gauge is σ = (∆R/R) / k, and the purpose of using a strain gauge is to accurately determine the strength and durability of a material. However, there are limitations to using strain gauges, such as the need for proper installation and calibration, a linear relationship between strain and stress, and unsuitability for corrosive or extreme temperature materials. While a strain gauge can be used
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A strain gauge has a unstrained resistance of 120 ohms, gauge factor of 2.0 is connected to steel girder so it experieces tensile stress. If strained resistance of gauge is 120.13 ohm. How do i calculate the tensile stress value?

I have looked all over the internet for equations relating but have not succeded, any help would be great
 
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If you look at the link it might help ...

http://en.wikipedia.org/wiki/Strain_gauge" [Broken]
 
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To calculate the tensile stress using a strain gauge, you will need to use the formula:

Stress = (Strained Resistance - Unstrained Resistance) / (Unstrained Resistance * Gauge Factor)

In this case, the strained resistance is 120.13 ohms and the unstrained resistance is 120 ohms. The gauge factor is given as 2.0.

Substituting these values into the formula, we get:

Stress = (120.13 - 120) / (120 * 2.0)
Stress = 0.13 / 240
Stress = 0.00054

Therefore, the tensile stress value is 0.00054. This is typically expressed in units of Pascals (Pa) or Megapascals (MPa). It is important to note that this formula assumes that the strain gauge is perfectly calibrated and that the steel girder is experiencing a uniform tensile stress. Any errors in calibration or non-uniform stress distribution may affect the accuracy of the calculated value.
 

1. How does a strain gauge measure tensile stress?

A strain gauge is a type of sensor that works by measuring the changes in resistance as a material is stretched or compressed. When a strain gauge is attached to a material, it deforms along with the material. This deformation causes a change in the resistance of the strain gauge, which can then be measured to determine the amount of strain and ultimately the tensile stress on the material.

2. What is the formula for calculating tensile stress with a strain gauge?

The formula for calculating tensile stress with a strain gauge is: σ = (∆R/R) / k, where σ is the tensile stress, ∆R is the change in resistance, R is the initial resistance of the strain gauge, and k is the gauge factor of the strain gauge.

3. What is the purpose of using a strain gauge to measure tensile stress?

The purpose of using a strain gauge to measure tensile stress is to accurately determine the amount of strain on a material. This can help engineers and scientists understand the strength and durability of a material, and can be used in a variety of industries such as aerospace, construction, and manufacturing.

4. Are there any limitations to using a strain gauge to calculate tensile stress?

Yes, there are some limitations to using a strain gauge to calculate tensile stress. One limitation is that the gauge must be properly installed and calibrated in order to get accurate measurements. The material being tested must also have a linear relationship between strain and stress, otherwise the results may not be accurate. Additionally, strain gauges are not suitable for measuring stress in materials that are highly corrosive or subject to extreme temperatures.

5. Can a strain gauge be used to measure tensile stress in real-time?

Yes, a strain gauge can be used to measure tensile stress in real-time. However, the speed and accuracy of the measurements will depend on the type of strain gauge and the equipment being used. Some strain gauges are designed for high-speed measurements, while others may require more time to get a reading. It is important to carefully select the appropriate strain gauge and equipment for the specific application in order to get the most accurate and timely results.

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