Testing

Case study

Osteotome Fracture
An osteotome unexpectedly failed during a plastic surgery operation. Veryst was hired to explain the failure.
PEEK Temperature Dependence
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.
Peeling of a Soft Polymer Film
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.
Plastic Clip Failure
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 Foam Testing & Modeling
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 with our PolyUMod® library.
Polymer Forming Simulation
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.
Polymer Material Models in Different FE Packages
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.
Real-Time Monitoring of Adhesive Curing and Kinetic Model Calibration
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.
Residual Tensile Strain Measurement in Polymers
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.
Silicon Nitride Thin Film Elastic Modulus
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.
Strength of Additively Manufactured Parts
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 Fracture
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.

Service

Abaqus Material Models
Veryst has designed test plans to calibrate material models to many advanced models in Abaqus, including the Bergstrom-Boyce (Hysteresis) model, Low Density Foam model, and Parallel Rheological Framework (PRF) models.
Adhesive Joints & Interfaces
Veryst assists clients with the selection of adhesive materials, development of bonding processes, and mechanical analysis of interfaces. We employ chemical characterization, mechanical testing, and advanced computational methods to design robust adhesively bonded structures and to understand delamination failures.
ANSYS Mechanical Material Models
Veryst has extensive experience selecting and calibrating material models for ANSYS, including the Bergstrom-Boyce model and other metal plasticity models.

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