You have a wide range of structural adhesive possibilities here. Normally, you require an adhesive that has been toughened with a rubber for this. Very rigid, quite brittle adhesives have been successful, however.

The most well-known application is the use of so-called “anaerobic” adhesives for the vibration proofing of threaded assemblies. Despite the brittle nature of these adhesives, they effectively adhere and fill the space between threads and prevent loosening of assemblies during vibration. They are tested using a Junker test, which is a mechanical test to determine the point at which a bolted joint loses its preload when subjected to shear loading caused by transverse vibration (ISO 16130 Standard test).

Some adhesive systems, like many polyurethanes, are inherently flexible, whereas others, such as reactive acrylics and epoxies, can be flexibilized to provide impact-proof assemblies. Their shock resistance can be measured using impact testing such as a block shear test (ISO 9653) or an impact wedge peel test (ISO 11343).

Epoxies are now used to provide crash-proof bonds in automotive body assembly operations. In concert with a seismic engineer, we also recently used one of these adhesives to provide bonds that can add resistance to earthquakes. This allowed a lowering of risk of damage to diesel tanks in a large manufacturing facility where welding on brackets was considered too dangerous.

Any views or opinions expressed in this column are those of the author and do not represent those of ASI, its staff, Editorial Advisory Board or BNP Media.