| Brittle: | (english) A brittle structure or material exhibits low ductility, meaning that it exhibits very little inelastic deformation before complete failure. |
| Center of Gravity (CG): | (english) The location of the resultant of gravity forces on an object or objects: sometimes called center of mass. |
| Centroid: | (english) Similar to the concept of center of gravity, except that it applies to a two dimensional shape rather than an object. For a given shape, the centroid location corresponds to the center of gravity for a thin flat plate of that shape, made from a homogeneous material. |
| Component (of a vector): | (english) Any vector can be expressed as a collection of vectors whose sum is equal to the original vector. Each vector in this collection is a component of the original vector. It is common to express a vector in terms of components which are parallel to the x and y axes. |
| Concentrated force: | (english) A force considered to act along a single line in space. Concentrated forces are useful mathematical idealizations, but cannot be found in the real world, where all forces are either body forces acting over a volume or surface forces acting over an area. |
| Connection: | (english) Connection is similar to the concept of support, except that connection refers to a relationship between members in a structural model. A connection restrains degrees of freedom of one member with respect to another. For each restrained degree of freedom, there is a corresponding force transferred from one member to the other; forces associated with unrestrained degrees of freedom are zero. See fixed connection and pin connection. |
| Couple: | (english) A system of forces composed of two equal forces of opposite direction, offset by a distance. A couple is statically equivalent to a moment whose magnitude equals the magnitude of the force times the offset distance. |
| Deflection: | (english) This word usually carries the same meaning as displacement, although it is sometimes used in place of deformation. |
| Deformation: | (english) A change in the shape of an object or material. |
| Degree of Freedom: | (english) A displacement quantity which defines the shape and location of an object. In the two dimensional plane, a rigid object has three degrees of freedom: two translations and one rotation. In three dimensional space, a rigid object has six degrees of freedom (three translations and three rotations). |