We distinguish five main types of load:
- Shear forces: the forces acting parallel to the adhesion. They are more common than tensile forces.
- Tensile forces: The forces acting perpendicular to the adhesive and spread evenly over the entire bonding surface.
- Splitting forces: These forces are not distributed uniformly over the adhesion area, but are concentrated in a limited space.
- Peel forces: These forces act only on the edge of the bonded area so that only a small amount of adhesion can counteract them.
- Shear and tensile forces are normally not a problem, due to he force being distributed over the entire adhesive surface.
Splitting and peeling stresses should be avoided in construction, because the force is distributed only on a small portion of the adhesive surface.
Other factors involved in adhesion are dynamically changing loads, vibrations, etc.