Experimental Stress Analysis with Strain Gauges

Understanding real material behaviour In many applications, calculations alone do not fully reflect how a component behaves in practice. Experimental Stress Analysis (ESA) is used to measure actual strain under real conditions and then the corresponding stress.

Experimental Stress Analysis (ESA) focuses on measuring real strain directly on a component by converting mechanical deformation into electrical signals. This provides insight into how a structure performs under real-world conditions and supports validation of design assumptions.

Zemic Experimental Stress Analysis strain gauges

• High Sensitivity and precision
• Self-Temperature Compensation (STC)
• Versatile geometries Wide temperature range
• Copper-plated terminals and pre-wired patterns

Measuring strain in practice

ESA strain gauges are used to measure extremely small deformations, down to 0.1 μm/m. This level of sensitivity makes it possible to detect small changes in structural behaviour that are not visible through calculations alone.

The measurements are taken directly on the component. In many cases, strain gauges with self-temperature compensation (STC) tailored to the test material are selected in order to minimise the effect of temperature on the measurement.

Applications of ESA strain gauges:

Strain gauges for ESA are used in a range of industries where accurate strain measurement is required.

Typical applications include:

• Aerospace: analysis of strain in safety-critical conditions, optimizing design and ensuring compliance with stringent aerospace standards.
• Structural health monitoring of infrastructure: monitoring of stress and long-term behaviour over time. Ensuring the safety, performance, and longevity of critical infrastructure and components, like bridges and pipelines.
• Material and fatigue testing: evaluation of durability under repeated loading.
• Concrete and civil engineering structures: validation of strain in concrete and large-scale builds during testing.
• PCB and PCBA tests: monitoring of strain in electronic assemblies, for ensuring the reliability and durability of PCBs.

These applications require accurate and reliable strain data to support testing, validation and performance assessment.

Measurement setup and reliability

Reliable ESA results depend on the correct setup and configuration.

Different measurement assemblies can be used, such as quarter bridge, half bridge and full bridge. Within these configurations, different strain gauge geometries are used to measure strain in specific directions, depending on the application and required analysis.

Strain gauges are designed to operate over a wide temperature range, from cryogenic conditions up to above 200°C. Accurate results also depend on proper installation, bonding and validation of the setup.

For each batch of produced ESA strain gauges, detailed technical data is provided, including:

• Gauge factor (per grid): Determined with metric precision for each individual grid in the strain gauge or rosette. This ensures that no approximate or nominal gauge factor is used that could alter the final measurements.
• Transverse sensitivity coefficient (Kt): This shows how sensitive the strain gauge is to forces that act sideways (perpendicular) instead of along its length. Knowing this helps correct measurement errors when force comes from different directions.
• Temperature dependance of the Gauge factor: This shows how the gauge factor changes when the temperature changes.
• Thermal output curve: This shows how the sensor reacts to temperature changes alone (without any mecanical force). It helps you to remove the temperature effect from the measurement so you can see only the real mechanical signal.

Zemic strain gauges for experimental stress analysis

Our portfolio supports both standard measurements and specialized test setups, with a range of geometries for different applications.

With consistent quality and detailed data per batch, Zemic strain gauges support accurate analysis in testing, validation and structural monitoring applications.

Interested in how our solutions fit your application? Make sure to look at our full range of ESA strain gauges or contact one of your experts.

Your strain gauge expert is ready to help you

For all your questions about the integration of ESA strain gauges, (custom-made) strain gauges, load cells or gauges for load cell manufacturing, please feel free to contact one of our strain gauge experts:

• https://www.zemiceurope.com/en/contacts