Non-Contact Measurement of Deflection: Evaluating Deformation and Stiffness Synchronized With Load

Three Problems That Occur When Deflection Cannot Be Measured Correctly

Depending on the choice of measurement method, the evaluation of deflection and deformation under actual operating loads can be completely incorrect.

Contact Methods Alter the Deflection of Flexible or Minutely Deforming Objects

Because dial gauges and displacement transducers push into the target with the contact force of the stylus, the amount of deflection itself changes for flexible, thin, or minute parts. If stiffness cannot be evaluated correctly due to errors caused by contact force, it can lead to incorrect design margins and quality judgments. In products, this manifests as unexpected damage, abnormal noise, or dimensional defects in subsequent processes or in the field. A measurement method with zero contact force is a prerequisite for evaluation.

Inability to Capture Dynamic Deflection Under Actual Operating Loads

With static single-point measurement, it is impossible to track the dynamic deflection behavior or the load-displacement relationship when an actual load is applied. If peak displacement or residual deformation after unloading is missed, the basis for evaluating stiffness and durability becomes weak. As a result, this leads to over-designing or, conversely, overlooking insufficient strength, inflating rework costs such as remaking prototypes or addressing defects after mass production.

Deflection Evaluation at Multiple Points or as a Distribution Becomes Dependent on Individual Skills

Measuring point by point manually prevents obtaining the deformation distribution for each part, causing uneven deflection or areas prone to warping to be missed. Evaluations vary depending on the operator and measurement method, delaying the understanding of stiffness trends and identification of causes. If mass production proceeds without being able to numerically demonstrate the validity of design changes, the risk of defective products reaching customers and design rework increases.

Flow From Load Application to Deflection Evaluation

Apply a load close to actual use, measure deflection synchronized with the load, and evaluate stiffness and durability from the load-displacement relationship.

1. 1 Jig installation and reference setting – Step 1. Fix finished products or parts to a jig under support conditions close to actual use, and install the sensor head on the target. Acquire the unloaded state as the reference (zero).
2. 2 Load application and load synchronization – Step 2. Apply loads simulating actual use in stages, and perform high-speed sampling of displacement (deflection) synchronized with the load signal. Map the load and displacement in a one-to-one relationship.
3. 3 Actual measurement of deflection and deformation – Step 3. Measure the profile displacement of the target surface using non-contact measurement with zero contact force. Acquire the deflection distribution at multiple points without contact force errors, even for flexible or minutely deforming objects.
4. 4 Stiffness and durability evaluation – Step 4. Calculate stiffness (slope) and residual deformation from the load-displacement curve. Evaluate changes over time under cyclic loading, and feed back to design and quality assurance.

Comparison of Deflection Measurement Methods

Depending on the measurement method, there are significant differences in contact force, measurable quantities, dynamic/multi-point evaluation, ease of setup, and applicability to moving or rotating bodies.

Reasons to Choose the LK-G5000 Series

The LK-G5000 Series uses a non-contact triangulation method to measure deflection and deformation without touching the target and with zero reaction force. There is no pressing error like with contact types, and load-displacement under actual operating loads can be acquired at high speed even for flexible or minutely deforming objects. Multi-point measurement with up to 12 heads streamlines stiffness and durability evaluation.

LK-G5000 Series Supporting Deflection and Deformation Measurement

A non-contact laser displacement sensor using the triangulation method. It measures deflection and deformation under actual operating loads with zero reaction force, and evaluates stiffness and durability from load-displacement.

Supporting Deflection and Deformation Measurement of Finished Products/Parts Under Actual Load — LK-G5000 Series

Ultra High-Speed/High-Accuracy Laser Displacement Sensor

This non-contact laser displacement sensor uses the triangulation method to measure deflection and deformation without touching the target and with zero reaction force. Even for flexible, thin, or minute parts, it captures displacement under actual operating loads as is, without pressing errors. With ultra-high-speed sampling of up to 392 kHz, dynamic deflection during load application and recovery (residual deformation) after load removal can be recorded in synchronization with the load, allowing stiffness and durability to be evaluated from the load-displacement curve. Simultaneous measurement of up to 12 heads and calculation functions also allow the distribution of multiple points, such as warpage and steps, to be grasped at the same time. More than 20 types of dedicated heads can be selected, ranging from rough surfaces to mirror surfaces and transparent materials.

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Inquiries regarding deflection and deformation measurement

Application Examples of Deflection and Deformation Measurement

These measurements are used for parts under actual load, running plates, and flexible/minute parts through non-contact deflection and deformation measurement.

Frequently Asked Questions About Deflection and Deformation Measurement

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