Determining the mechanical behavior of bones can be challenging given the complexity of the materials that make up the bone and the geometry. Assessing the mechanical behavior of whole bones, especially rib bones, can aid in understanding the relationship between loading and injury risk as many rib injuries are due to impact type events.
Foam materials often exhibit high strain rate sensitivity, with large increases in stiffness as materials are loaded at higher rates. Veryst performed high-rate compression tests of a foam material, reaching impact strain rates of over 1500/s.
Polymers exhibit significant temperature-dependent mechanical response. Veryst tested a PEEK material at multiple temperatures and calibrated the PolyUMod® Three Network (TN) material model for finite element simulation.
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.
Pop-up rubber jumpers are fun toys that unexpectedly jump and pop when placed on a flat surface after they are inverted. The poppers are hemispherical rubber domes which can be easily inverted inside-out, a process that stores elastic energy in the rubber material. This case study showcases how simulation can effectively be used to unravel complex nonlinear phenomena such as the inversion and jump of a popper toy.
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.
To compare the performance of two gas humidification devices, Veryst Engineering performed gas flow testing, device examination, and CFD analysis.
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.
The peel test is widely used to measure the adhesion of thin, compliant films to rigid substrates. An accurate model of the peeling mechanics is required to extract the interface adhesion energy. Veryst used the PolyUMod® material model library along with a cohesive zone model of interface adhesion to simulate the peeling of a soft viscoplastic film from a rigid substrate.
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.
Obtaining accurate results from finite element analyses of polymers is not easy. Polymers are often highly temperature- and rate-dependent, exhibiting significant stress-relaxation, creep, and recovery. In this forming case study, Veryst examines the steps required to produce an accurate constitutive model of an example polymer, polyether ether ketone (PEEK), and shows the consequences of oversimplification.
All commercial FE packages provide material models for polymers, but Veryst Engineering’s PolyUMod® material library has advanced material models at the leading edge of polymer mechanics. We demonstrate the accuracy of a PolyUMod material model with native material models from Abaqus, ANSYS, and LS-DYNA.
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.