Failure Analysis

Seminar

Failure Predictions of Rubbers and Thermoplastics Using FEA

Predicting failure of different polymers can be difficult due to material nonlinearities and sensitivity to the load environment. In this class we will discuss different techniques that can be used to predict both brittle and ductile failure, including fatigue, of different types of polymers.

Failure Predictions of Rubbers and Thermoplastics Using FEA 2019

Predicting failure of different polymers can be difficult due to material nonlinearities and sensitivity to the load environment. In this class we will discuss different techniques that can be used to predict both brittle and ductile failure, including fatigue, of different types of polymers.

Case study

Broken Rail Train Derailment
A train derails with an ensuing fire and evacuation of a neighborhood. What was the root cause of the derailment?
Cohesive Zone Model (CZM) Calibration
Cohesive zone modeling is a powerful tool for predicting delamination in adhesively bonded structures. Veryst engineers use their expertise in experimental and computational fracture mechanics to calibrate cohesive zone models for accurate prediction of adhesive failure.
Cranial Perforators
Medical devices, such as the cranial perforator here, show imperfections that are rejected by physicians. Veryst investigates the source of these imperfections and recommends steps to remove them.
Delamination in Microfluidic Valves
A commonly encountered failure mode in microfluidic devices is delamination between adjacent device layers. Veryst examined the influence of control channel geometry on the delamination pressure of a pneumatic microfluidic valve using finite element analysis.
Design of Reinforced Hoses
A high-strength reinforced hose failed in service under normal operating conditions well before its intended design life. Inspections of the subject hose revealed that failure was mainly due to delamination.
Fatigue Failure of a Plastic Lever
A plastic lever on a consumer product failed unexpectedly in service. Veryst determined the root cause of the failure and provided design recommendations to prevent similar failures from occurring again.
FTIR microscopy analysis of thermoplastic solvent bonding
Solvent bonding, although an effective way to join thermoplastics, can pose process challenges that reduce bond strength. Veryst uses FTIR microscopy to characterize the interface structure of solvent bonds, obtaining a “chemical image” of the solvent-bonded interface. The result is a full understanding of the bond and ways to improve its strength and reliability.
Guidewire Entanglement
Guidewires and stents can become entangled during deployment. Veryst assists in determining whether product design plays any role in these events.
Impact Fracture Toughness of Adhesive Joints
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.
Osteotome Fracture
An osteotome unexpectedly failed during a plastic surgery operation. Veryst was hired to explain the failure.
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.
Small Sample Size Lifetime Prediction
How long will a product last? This is an essential question during product development, but accurately predicting product end of life can be hampered by limited data. Veryst provides a method for the reliability engineer to predict end of life with a small sample size and shows how the proper lifetime prediction method can eliminate unexpected field failures.
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.

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