Given geometry, material, restraints, and loads, Scan&Solve™ computes several types of quantities that are useful in understanding predicted structural properties of the model:
Displacements. The primary computed property is displacement – a vector (x-, y-, z-) quantity measuring where each point of the body moves after the loads are applied. The total displacement is a (scalar) magnitude of the displacement vector. Displacement is measured in units of length. Displacements are important for a number of reasons:
Recall that
linear static analysis is really a “small displacement theory” that assumes that the solid shape does not change very much. Thus, the computed displacements can be interpreted as a first approximation of the actual deformation indicating tendency and magnitude of deformation. They can be magnified and visualized in the deflected view. But if the computed displacements are large, the actual deformation may be very different.
Generally speaking, predicted values of displacement are always more accurate than predicted values of strains and stresses, because displacement is the primary quantity directly computed by solving a system of linear equations. In contrast to stresses, displacements have finite magnitude and do not have singularities at any points.
Large displacements are not necessarily bad; they simply indicate flexibility of the system to move or deform.
Because displacement is the primary computed quantity, it's accuracy is necessary for accurate prediction of all other properties. In particular, all computation of stresses, strains, and failure criteria require accurate displacements.
For the same reason, displacements provide the best measure for comparing consistency, accuracy, and convergence of computations – in the same system or between different systems.
Strains. Informally, strains measure (directional) rate of deformation within the body. It is dimensionless because it measures change of length per unit length. Just like stress, one-dimesional strain can be measured in any direction, and there is one-to-one correspondence between components of stress and strain (normal, shear, principal, etc.).
At every point in the body, it is possible to orient the coordinate system in such a way that only normal strains acting in the three orthogonal coordinate axis directions remain. These three components of strain are called principal strains. The value and the direction of the principal strains changes at every point.
Generally, strains are proportional to stresses (i.e. large strains imply large stresses), and in linear elasticity stresses and strains are directly related by proportionality constants according to Hooke's law. Strains may be also used directly to predict material failures.
Each of the above quantities may be visualized and queried for min/max/point values using the controls on the [View] tab.