Compressive Force
A compressive force (also called a compression force, opposite of tensile force; Norsk: trykkraft) is a force that pushes or squeezes a structural member together along its longitudinal axis.
In a truss, when a member is subjected to a compressive force, the forces at its two ends act toward the member, tending to shorten or compress it.
In simple words:
Compressive force = a pushing force that tends to shorten or squeeze a member.

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