The principle of Experimental Stress Analysis (ESA) consists in using strain gauges to measure strains on a component's surface. The absolute value and direction of the mechanical stresses are determined from the measured strains and the known properties of the material (modulus of elasticity and Poisson’s ratio). These calculations are based on Hooke’s Law which applies to the elastic deformation range of linear-elastic materials. Learn more by clicking here.
Strain Gauges Fundamentals
Strain gauges have been around for almost 80 years and continue to be key assets to measure fatigues and test materials for productivity and safety reasons. But how do I calculate material stress from strain? How can I select the right strain gauge and install it correctly? Our experts dug deep to provide you with their best answers to these and all important questions about measuring with strain gauges.
- Basics of Strain Measurements and Experimental Stress Analysis
- Selecting the Right Strain Gauges, Adhesive, Covering Agents and More
- Installations of Strain Gauges: All there is to Know
- Acquiring Data with the Right Hardware and Software
- Reduction and Elimination of Measurement Errors
- Training, Webinars and References on Strain Measurements
Basics of Strain Measurements and Experimental Stress Analysis
The Wheatstone bridge is well suited for the measurement of small changes of a resistance and is, therefore, also suitable for measuring the resistance change in a strain gauge. It is commonly known that the strain gauge transforms strain applied into a proportional change of resistance. Find more about the application of Wheatstone Bridge Circuits here.
The reference book on Experimental Stress Analysis using strain gauges
Get a complete overview of the topic of "An Introduction into Measurements using Strain Gauges" - in Karl Hofmann's 250-page reference book.
Selecting the Right Strain Gauges, Adhesive, Covering Agents and More
Strain gauges are usually applied to the surface of the measurement object using adhesives. Here you can learn how to select the correct adhesive according to the material and temperature range. This page also provides tips for preparing a measuring point to ensure good bonding for strain transfer.
The quality of a measurement with strain gauges depends essentially on the type of installation and design of the measuring point. A thorough preparation of the installation surface, correct connection, and protective covering are important factors for problem-free results.
Installation of Strain Gauges: All There is to Know
Click here for a quick overview on how to prepare your material for an effective strain gauge installation. Apply the suggestions given by our highly-skilled experts for a successful installation on concrete, plastics, fiber-reinforced material, among others.
This training video shows you all the necessary step by step for a successful strain gauge installation. No measurement skills or previous installation experience is required.
Some environments are not suitable for bonding strain gauges due to very low temperatures or excessive dust formation, e.g. on construction sites. Weldable strain gauges are the best choice for being used in this type of environments. Watch our video on how to weld your strain gauge correctly.
In many cases, measuring strain on an object is done in a short timeframe. If the strain gauge is improperly installed, false measurements can be obtained. Watch this video to learn how to install gauges in the most effective way.
Practical hints for the installation of strain gauges
Get a complete overview of the topic of "Practical Hints for the Installation of Strain Gages"- in Karl Hofmann's reference book.
Reduction and Elimination of Measurement Errors
There are possible sources of error when strain gauges are used in experimental stress analysis. Learn how to successfully assess measurement uncertainty already in the design stage by clicking on the title above.
Unwanted temperature effects can affect the measurement result when using strain gauges. Find practical assistance on how to minimize these effects or compensate for them entirely. Learn more by clicking on the title above.
Particularly electrical resistance changes in the cable that connects the measuring pints to the measuring device, e.g. due to temperature variations, have negative effects in the measurement. Click above to find out more.
Acquiring Data with the Right Hardware and Software
In this tutorial you will learn how to set up strain gauge rosettes using HBM's catman®AP data acquisition software and a QuantumX MX1615 data acquisition system.