Contact Force
Contact force measurement simulation and experimental validation

Expressions for determining the value of the impact force as reported in the literature and incorporated into code provisions are essentially quasi-static forces for emulating deflection.
Quasi-static forces are not to be confused with contact force which is generated in the vicinity of the point of contact between the impactor and target, and contact force is responsible for damage featuring perforation and denting.
The distinction between the two types of forces in the context of impact actions is not widely understood and few guidelines have been developed for their estimation.