Understanding composite materials’ impact response as a function of fiber direction is important for a wide range of uses, from automotive applications for crashworthiness to consumer product uses for drop and impact resistance. Veryst evaluated the high strain rate response of both glass fiber and carbon fiber reinforced PEEK (polyether ether ketone) using the Split Hopkinson Pressure Bar test method.
This case study demonstrates the testing and calibration of a polycarbonate material at a high strain rate of 1000 sec-1. The testing was done with the Split Hopkinson Pressure Bar (SHPB) system and the calibration is performed with the MCalibration® software, originally developed by Veryst Engineering.
Veryst developed a new test method for measuring fracture toughness under impact loading that does not require measurement of load or crack length. We have used this method to help clients in the automotive and electronics industry understand how adhesives fail under impact conditions.
Veryst used topology optimization to design an additively manufactured bracket for adhesive assembly and then used cohesive zone modeling to predict the strength of the bonded joint.
An osteotome unexpectedly failed during a plastic surgery operation. Veryst was hired to explain the failure.
PEEK materials are increasingly used in a variety of industries with elevated temperature applications. This example shows how Veryst Engineering developed a temperature-dependent, nonlinear model of PEEK behavior for use in commercial FEA codes.
A plastic clip used to retain a patient support failed, resulting in an occupant death. Veryst was asked to determine the cause of failure.
Polymer foams may exhibit extreme strain rate-dependence due to their structure. The low stiffness means testing the materials at high strain rates is particularly difficult. Veryst has developed multiple test methods to test and model these materials.
Designing an assembly process using a thermoset adhesive can be challenging without an understanding of the adhesive curing kinetics. Veryst engineers use FTIR spectroscopy to analyze curing and optimize processing steps.
Materials that have been deformed past their yield point and into the plastic strain region often display permanent deformation upon removal of load. How much of this deformation is truly permanent? Veryst has developed a method to measure the residual strain of materials following unloading as a function of time.
Knowledge of thin film mechanical properties is important for device operation, reliability, and simulation. Veryst measured the elastic modulus of a low stress silicon nitride thin film using nanoindentation and validated the technique with atomic force microscopy.
Medical devices, combination products, consumer products, and manufacturing processes often include components that slide past each other. These products and processes can fail when the friction forces between the surfaces are too high, due to surface roughness, lubrication, materials, or environmental conditions. Here Veryst introduces a specialized fixture to measure the friction between a small metal wire and three polymer materials, to select a backup supplier for dual sourcing that would maintain low friction in a medical device.
Veryst can predict the ultimate strength and failure modes of design concepts generated using topology optimization and produced using additive manufacturing. We use advanced finite element analysis (FEA) that accounts for the nonlinear behavior of the material being used to make the part.
Tempered and plate glass are manufactured to produce very different fracture patterns when they break. Veryst can use this information to identify installed glass products and discuss the implications of their use.
Shape memory alloys, like nickel titanium alloy (nitinol), are common in medical device applications. Nitinol is often used in fine wire form and can be difficult to test. Veryst has developed methods to test fine nitinol wires in uniaxial tension at different temperatures to obtain a stress-strain curve.