▶Stress/Strain/Hook's law/Poisson's ratio/Plane element/Iso element (응력/변형률/후크의 법칙/푸아송비) Stress (응력) Stress are the internal force in a element resisting the deformation. Assume that you let your cell phone on the table and push the phone vertically. If you pushed the phone with force as much as not destroy the phone, the phone maintain itself becasue it resists your push force. The force resist..