The Mechanical Properties of Structural Adhesives

Three of the mechanical properties of elastomeric structural adhesives were investigated. Creep, impact, and the effect of strain rate were measured for eight adhesives. The rupture energy at impact ranged from 5.3 to 19.0 ft. pounds per square inch of bond for different adhesives at ambient temperature. The rupture energy ranged from 2.7 to 4.5 ft. pounds per square inch of bond for adhesives at -40 degrees F. Higher strain rates decreased the energy necessary to rupture the adhesive bond. Strain-rate had no effect on failure stress. The adhesives were tested at 90 psi nominal shear stress. The twenty-eight day test was at ambient temperature while the seven day creep test was at 158 degrees F. At ambient temperature, four adhesives failed and the rest showed total deformations of less than five mils. At 158 degrees F, adhesive 7 deformed less than four mils but the other adhesives failed. More research is needed on these adhesives to fully understand their properties and to determine which applications they are suited for