Stiffness or rigidity: a property of a material or body that resists deformation under applied forces (technical/engineering term).
この素材は剛性が高く、たわみにくい。
This material has high stiffness and does not bend easily.
車のボディ剛性を上げると操縦安定性が向上することが多い。
Increasing the body stiffness of a car often improves handling stability.
設計では剛性と靱性のバランスを考慮する必要がある。
In design, it is necessary to consider the balance between stiffness and toughness.