# Glossary

## Amazon EC2 (Elastic Compute Cloud)

A mixture of services, each with its own individual features, used to create a single architecture and launch virtual computing environments (instances) in the AWS cloud.

## Amazon S3 (Simple Storage Service)

A storage service that stores data as objects within buckets offered by AWS.

## AWS (Amazon Web Services)

An online platform that provides scalable and cost-effective cloud computing solutions, provided by Amazon.

## Cholesky Decomposition

A direct solution method that decomposes a symmetric, positive-definite matrix into a product of a lower unit triangular matrix (L), a diagonal matrix, (D) and its transpose (LT).

## Cloud Computing

The use of a network of remote servers to store, manage and process data.

The use of computers to aid in the creation, modification, analysis or optimization of 3D designs.

An iterative solution method applicable to numerically solving sparse systems of linear equations which are too large to be handled by direct methods such as Cholesky Decomposition.

## Constraint

A mathematical equation that the solution must satisfy. SPARSELAB currently supports displacement constraints, which are applied to all the nodes of selected surfaces.

## Degree of Freedom (DOF)

The unknown variables that are solved in the resulting system of linear equations.

## Density

The mass per unit volume of a material.

## Displacement

A vector quantity for the change in position of a node. SPARSELAB calculates nodal displacements to understand how the geometry will behave when subject to loads.

## Element

The basic building blocks connected together to form a mesh. SPARSELAB uses triangle and linear tetrahedral elements.

## Finite Element Analysis (FEA)

The study or analysis of a physical phenomenon using the Finite Element Method (FEM); a general numerical method for solving partial differential equations.

## Mesh

The space discretization of the geometry into a set of elements with a finite number of nodes. It represents the numerical domain for the solution of the Finite Element Method, over which a system of linear equations are solved.

## Node

A point in space with a specific number of degrees of freedom (DOFs). Nodes exist at the vertices of elements. For 3D linearized elasticity, each node will have 3 degrees of freedom.

## Partial Differential Equation (PDE)

A mathematical equation involving the partial derivatives of an uknown function of 2 or more variables with respect these variables.

## Poisson Ratio

The ratio of lateral strain (change in width per unit width of a material) to axial strain (change in length per unit length) due to a force.

## Polyhedron

A three-dimensional shape with flat polygonal faces, straight edges and vertices.

## SLAB

The file format for SPARSELAB projects.

## Static Stress Analysis

The study, analysis or calculation of the effects of steady loads on a physical structure, assuming no inertia or damping effects such as those caused by time varying loads.

## STEP

Standard for the Exchange of Product Data. It is the standard exchange format for creating, modifying and sharing 3D designs. It is supported by all major CAD software.

## Strain

The displacement gradient as a symmetric tensor. The x-component of the strain is the partial derivative of the vertical displacement with respect to x.

## Stress

The force across a small boundary per unit area of that boundary for all orientations of the boundary, as a symmetric tensor.

## Tetrahedron

A convex polyhedron composed of 4 vertex corners and 4 triangular faces.

## WebAssembly (WASM)

A type of portable binary code that is executed by modern web browsers, enabling high-performance web applications. It is a low-level assembly-like language that runs with near-native performance.

## WebGL

A graphics API for rendering high-performance interactive 2D and 3D graphics to be used in web applications.

## Young's Modulus

The measure of stiffness of an elastic material, defined as the ratio of tensile stress to tensile strain.