This webinar will introduce the mechanics of interfacial stress and delamination in layered structures, with the goal of helping engineers better predict and prevent delamination failures. We will survey the sources and basic characteristics of mechanical stress at interfaces as well as introduce the practical experimental, analytical, and computational approaches available for analyzing delamination failures.
An adhesive joint was failing in the field. Veryst used DSC to investigate and determined the root cause to be improper curing of the adhesive.
Joining polyolefins such as polyethylene and polypropylene with adhesives can be challenging. Polyolefins have low surface energy, which creates weak bonds between the polyolefin material and the adhesive. Veryst used corona discharge plasma treatment to improve the bond strength and create a more robust joint.
Impact modeling of polymers is important given their use in consumer products as both structures and impact protection. Accurate FE models of impact events require high rate testing, advanced modeling, and a thorough understanding of polymer failure.
A train derails with an ensuing fire and evacuation of a neighborhood. What was the root cause of the derailment?
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.
Medical devices, such as the cranial perforator here, show imperfections that are rejected by physicians. Veryst investigated the source of these imperfections and recommended steps to remove them.
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.
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.
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.
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.
Guidewires and stents can become entangled during deployment. Veryst assisted in determining whether product design plays any role in these events.
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.