Ultimate Strength Term used to describe the maximum unit stress a material will withstand when subjected to an applied load in a compression, tension, or shear test. Normally, changes in area due to changing load and necking are disregarded in determining ultimate strength.
UniCell The closed-cell derivative of the UniSemble. The exemplar UniCell is a UniSemble in which all of the figurative TRDs have a void at their respective centers.
UniCore The open-cell derivative of the UniSemble is the UniCore. Removing every fourth figurative TRD from the UniSemble architecture produces the UniCore architecture, which has two sets of voids that are mostly continuous. The exemplar UniCore has porosity of approximately 30%.
UniFrame The edge-wise framework of the UniSemble architecture.
UniSemble A unit cell of a close-packed assembly of twelve conjoined Truncated Rhombic Dodecahedra (TRDs) arranged symmetrically around a thirteenth TRD. The UniSemble is a closed-cell architecture. The exemplar UniSemble has a void array that gives it a porosity of less than ten percent, but its porosity can range from as little as one percent to approaching 50 percent. The UniSemble is the primary RMT Architecture.
Vault An arched surface.
Vertex (Vertices) One (or more) of the points at which lines or planes meet in a figure; for example, a corner of a polygon or polyhedron.
Vierendeel Truss A truss with rectangular panels and rigid joints. The members of a Vierendeel truss are subject to strong nonaxial forces.
Viscoelasticity This property, possessed by all plastics to some degree, dictates that while plastics have solid-like characteristics such as elasticity, strength and form-stability, they also have liquid-like characteristics such as flow depending on time, temperature, rate and amount of loading. Materials that demonstrate both viscous and elastic behavior under applied stress are called viscoelastic.
Viscosity, MFR, MVI, and MV Viscosity is the resistance to steady flow shown within the body of a material. It is internal friction or the measure of a polymer melt’s resistance to flow. In testing: the ratio of the shearing stress to the rate of shear of a fluid. Which ‘Newtonian viscosity’, the ratio of shearing stress to rate of shearing strain is constant. In non-Newtonian behavior – which is the usual case with plastics – the ratio is not constant but varies with the shearing stress. Such a ratio is often called the apparent viscosity at the corresponding shearing stress. It represents one point on the flow curve. MFR, or melt flow rate, is the mass of thermoplastic material extruded in a given time through a defined orifice under specified conditions. Also called "flow rate." The expression MVI, or melt volume index, equals MVR. MV, or melt viscosity, is a measure of a polymer at a given temperature at which the molecular chains can move relative to each other. It is expressed as the quotient of the real shear stress t and the real rate of shear y. Melt viscosity is considerably dependent on the molecular weight: the higher the molecular weight the greater the entanglements and the greater the melt viscosity.
Void The space between particles or other units in a compact, such as a close-packing of spheres or TRDs. In Reflexive Material Technology, a three-dimensional zone through which significant forces are not transmitted. A void can be empty, or it can be filled with a material of less stiffness (see Modulus of Elasticity) than the material of the skeleton of an RMT structure.