In many cases your analysis results represent a significant investment of computational effort. As a result, you will often want to reduce computation costs by utilizing results from an analysis that has already been performed. In other cases your overall analysis history will be comprised of distinct Abaqus jobs, each representing a portion of the response history of the model. Abaqus provides the following analysis continuation techniques:

• Abaqus allows you to restart an analysis, as long as you request that certain files containing model and state data be saved in the original analysis. See “Restarting an analysis,” Section 9.1.1.

• You can perform part of an analysis with Abaqus/Standard or Abaqus/Explicit and continue the analysis with the other product. You can transfer results from Abaqus/Standard to Abaqus/Explicit, from Abaqus/Explicit to Abaqus/Standard, and from Abaqus/Standard to Abaqus/Standard. See “Transferring results between Abaqus analyses: overview,” Section 9.2.1.

All Abaqus models involve certain abstractions. In addition to the traditional abstractions associated with the finite element method, you can include techniques in your model to obtain more cost-effective solutions. Abaqus provides the following techniques for modeling abstractions:

• You can create substructures by grouping a number of elements together and retaining only the degrees of freedom needed to interface with adjacent structures. This technique is particularly useful when a substructure is to be reused in the same analysis, in different analyses, or by different analysts. See “Using substructures,” Section 10.1.1.

• You can analyze local regions of a model in greater detail and interpolate the solution results from a larger coarser global model. See “Submodeling: overview,” Section 10.2.1.

• You can create a three-dimensional model in Abaqus/Standard by revolving various forms of axisymmetric and three-dimensional model sectors about an axis of symmetry (see “Symmetric model generation,” Section 10.4.1). You can also transfer the solution obtained in an original axisymmetric model to the new model (see “Transferring results from a symmetric mesh or a partial three-dimensional mesh to a full three-dimensional mesh,” Section 10.4.2). In addition, for models that exhibit cyclic symmetry you can extract eigenmodes and perform mode-based steady-state dynamic analysis by modeling only a single repetitive sector of the model (see “Analysis of models that exhibit cyclic symmetry,” Section 10.4.3).

• You can define a complex beam cross-section, including multiple materials and complex geometry, and automatically generate beam element cross-section properties. See “Meshed beam cross-sections,” Section 10.6.1.

• Using the extended finite element method, you can model discontinuities, such as cracks, as an enriched feature without creating a mesh to match the geometry of the discontinuity. See “Modeling discontinuities as an enriched feature using the extended finite element method,” Section 10.7.1.

Certain analysis techniques do not fall into a general classification and are grouped here as special-purpose techniques. Abaqus provides the following special-purpose techniques:

• You can use the inertia relief technique as an inexpensive alternative to performing a full dynamic analysis on a free or partially constrained body subjected to loads derived from rigid body accelerations. See “Inertia relief,” Section 11.1.1.

• You can selectively remove, and later reintroduce, parts of a model. See “Element and contact pair removal and reactivation,” Section 11.2.1.

• You can introduce small imperfections into a model, typically for postbuckling analysis. See “Introducing a geometric imperfection into a model,” Section 11.3.1.

• You can evaluate fracture performance through contour integral evaluation, through crack propagation modeling techniques, or by using line spring elements in conjunction with shell elements. See “Fracture mechanics: overview,” Section 11.4.1.

• You can model coupling between the deformation of a fluid-filled structure and the pressure exerted by a contained fluid (see “Surface-based fluid cavities: overview,” Section 11.5.1).

• In Abaqus/Explicit you can use the mass scaling technique to control the stable time increment and increase computational efficiency. See “Mass scaling,” Section 11.6.1.

Adaptivity techniques enable modification of your mesh to obtain a better solution. Abaqus provides the following adaptivity techniques:

• You can use ALE adaptive meshing to control mesh distortion or to model material loss. See “ALE adaptive meshing: overview,” Section 12.2.1.

• You can use adaptive remeshing with Abaqus/Standard and Abaqus/CAE to iteratively improve your mesh to obtain a more accurate solution. See “Adaptive remeshing: overview,” Section 12.3.1.

• You can use mesh-to-mesh solution mapping as part of a mesh replacement strategy for distortion control. See “Mesh-to-mesh solution mapping,” Section 12.4.1.

You can use Abaqus/Explicit to simulate extreme deformation, up to and including fluid flow, in an Eulerian analysis. Eulerian materials can be coupled to Lagrangian structures to analyze fluid-structure interactions. See “Eulerian analysis,” Section 14.1.1.

You can perform multiphysics analyses by coupling two Abaqus analyses or by coupling Abaqus with third-party analysis programs. In Abaqus/Standard you can read scalar nodal output generated in an analysis into subsequent analyses as predefined fields for sequentially coupled multiphysics workflows. See “Co-simulation: overview,” Section 16.1.1, and “Sequentially coupled multiphysics analyses using predefined fields,” Section 16.2.1.

You can use the flexibility of user subroutines to increase the functionality of Abaqus. See “User subroutines and utilities,” Section 17.1.

You can use design sensitivity analysis (DSA) techniques to determine sensitivities of responses with respect to specified design parameters. You can use these techniques for design studies within Abaqus/Standard or in conjunction with third-party design optimization tools. See “Design sensitivity analysis,” Section 18.1.1.

You can use parametric studies to perform multiple analyses in which you can systematically vary modeling parameters that you define. See “Scripting parametric studies,” Section 19.1.1, and “Parametric studies: commands,” Section 19.2.