Meaning
Non-contact measurement technique utilizing digital cameras and image correlation algorithms analyzes surface deformation across an entire specimen or part. During the testing of moulded parts or sheet thermoforming, optical strain mapping reveals localized stress concentrations and strain distributions that point sensors miss.
Defect Detection
Inhomogeneous strain distribution during forming processes often leads to structural weaknesses. By using optical strain mapping, engineers can visualize exactly where high strain is concentrated on a part under load. This allows for the rapid identification of weak spots, enabling design modifications before the mould geometry is finalized.
Spotting these strain concentrations early prevents the production of molded components that are prone to premature cracking or mechanical failure under normal service conditions.
Simulation Validation
Finite element simulations of polymer deformation must be validated against real-world tests to ensure accuracy. Comparing simulation results with optical strain mapping data confirms whether the hyperelastic model has been calibrated correctly. This verification is essential for reducing trial-and-error iterations when optimizing stretch blow moulding processes.
Forming Behavior
Anisotropic material behavior in extruded sheets influences how a polymer deforms in the mould. Using optical strain mapping during sheet stretching helps characterize the orientation of polymer chains and its effect on structural strength. This leads to better raw material selection and more predictable part performance.
