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+---
+type: concept
+title: "Abaqus Element Library"
+complexity: advanced
+domain: computational-mechanics
+created: 2026-05-29
+updated: 2026-05-29
+address: c-000056
+aliases:
+  - ABAQUS element library
+  - Abaqus elements
+tags:
+  - concept
+  - finite-element-method
+  - abaqus
+  - element-formulation
+status: current
+related:
+  - "[[Abaqus Theory Manual]]"
+  - "[[Abaqus-Analysis-User-s-Guide-Volume-I|Abaqus Analysis User's Guide Volume I]]"
+  - "[[ABAQUS]]"
+  - "[[Abaqus Spatial Model Definition]]"
+  - "[[Abaqus Surface and Assembly Modeling]]"
+  - "[[Isoparametric Finite Elements]]"
+  - "[[Solid Element Stiffness Integration]]"
+  - "[[Reduced Integration and Hourglass Control]]"
+  - "[[Hybrid Incompressible Elements]]"
+sources:
+  - "[[Abaqus Theory Manual]]"
+  - "[[Abaqus-Analysis-User-s-Guide-Volume-I|Abaqus Analysis User's Guide Volume I]]"
+---
+
+# Abaqus Element Library
+
+## Definition
+
+The Abaqus element library is the collection of finite element formulations used to model continua, structures, interfaces, fluids, constraints, and special analysis features in Abaqus.
+
+## How It Works
+
+The manual presents isoparametric interpolation as the central continuum-element pattern: the same shape-function framework maps the element geometry and interpolates displacement or other field variables. Element virtual work is evaluated by numerical integration over integration points, where strains, stresses, state variables, and material tangent contributions are computed.
+
+The library includes continuum solids, infinite elements, membranes, trusses, beams, shells, rebars, hydrostatic fluid elements, and special-purpose elements. It also supports multi-field elements where scalar variables such as temperature, pressure, electric potential, or concentration use their own interpolation alongside displacement.
+
+The user guide adds the input-file side of the library: an element definition pairs an element number and connectivity with an element type, then uses element sets, sections, surfaces, and assembly instances to connect that formulation to materials, loads, constraints, and output.
+
+## Formulation Choices
+
+- Full integration improves rank and suppresses zero-energy modes but may lock in bending or incompressible limits.
+- Reduced integration can lower cost and improve some strain estimates but may introduce hourglass modes.
+- Selective reduced integration and hybrid elements address volumetric locking and incompressibility.
+- Second-order elements are often preferred for smooth elliptic problems, while first-order or enriched elements are common in localization, contact, and severe nonlinearity.
+
+## Connections
+
+- [[Isoparametric Finite Elements]] gives the common mapping and interpolation language.
+- [[Reduced Integration and Hourglass Control]] explains the main under-integration tradeoff.
+- [[Hybrid Incompressible Elements]] explains the mixed treatment used when displacement-only elements become too stiff.
+- [[Solid Element Stiffness Integration]] is the local stiffness assembly case for three-dimensional continuum elements.
+- [[Abaqus Spatial Model Definition]] shows how element types and connectivities are entered in a model.
+- [[Abaqus Surface and Assembly Modeling]] shows how element faces and instances become interfaces, loads, and constraints.
+
+## Sources
+
+- [[Abaqus Theory Manual]]
+- [[Abaqus-Analysis-User-s-Guide-Volume-I|Abaqus Analysis User's Guide Volume I]]