Pin support: |
(english) In two dimensions, a pin support restrains two translation degrees of freedom but does not restrain rotation. When considering reaction forces, a pin support is usually considered to have two force components: one each about the x and y axes respectively. |
Pressure: |
(english) Pressure is a similar idea to stress, the force intensity at a point, except that pressure means something acting on the surface of an object rather than within the material of the object. When discussing the pressure within a fluid, the meaning is equivalent to stress. |
Roller support: |
(english) In two dimensions, a roller support restrains one translation degree of freedom. |
Shear: |
(english) An system of internal forces whose resultant is a force acting perpendicular to the longitudinal axis of a structural member or assembly: sometimes called shear force. |
Shear stress: |
(english) Stress acting parallel to an imaginary plane cut through an object. |
Shear strain: |
(english) Strain measuring the intensity of racking in the material. Shear strain is measured as the change in angle of the corners of a small square of material. |
Shear modulus: |
(english) The ratio of shear stress divided by the corresponding shear strain in a linear elastic material. |
Stability: |
(english) Stability is best defined as the opposite of instability, which is the occurrence of large structural deformations which are not the result of material failure. |
Statically determinate: |
(english) A statically determinate structure is one where there is only one distribution of internal forces and reactions which satisfies equilibrium. In a statically determinate structure, internal forces and reactions can be determined by considering nothing more than equations of equilibrium. |
Statically equivalent: |
(english) Two force systems are statically equivalent when their resultants are equal. Physically, this means that the force systems tend to impart the same motion when applied to an object; note that the distribution of resulting internal forces in the object may be different. |