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wiki/concepts/Finite Element Contact Formulation.md

@@ -4,7 +4,7 @@ title: "Finite Element Contact Formulation"
 complexity: advanced
 domain: computational-mechanics
 created: 2026-05-29
-updated: 2026-06-01
+updated: 2026-06-02
 address: c-000060
 aliases:
   - contact formulation
@@ -33,11 +33,16 @@ related:
   - "[[Abaqus Special-Purpose Interaction Elements]]"
   - "[[Nonlinear Finite Element Analysis]]"
   - "[[ABAQUS]]"
+  - "[[Midas FEA Static Contact Analysis]]"
+  - "[[Midas FEA Interface Elements and Nonlinearities]]"
+  - "[[Midas NFX Contact Analysis]]"
 sources:
   - "[[Abaqus Theory Manual]]"
   - "[[Abaqus-Analysis-User-s-Guide-Volume-I|Abaqus Analysis User's Guide Volume I]]"
   - "[[Abaqus-Analysis-User-s-Guide-Volume-IV|Abaqus Analysis User's Guide Volume IV]]"
   - "[[Abaqus-Analysis-User-s-Guide-Volume-V|Abaqus Analysis User's Guide Volume V]]"
+  - "[[Midas-FEA-Analysis-Manual|Midas FEA Analysis Manual]]"
+  - "[[Midas-NFX-Analysis-Manual|Midas NFX Analysis Manual]]"
 ---
 
 # Finite Element Contact Formulation
@@ -58,6 +63,10 @@ The user guide adds the model-definition layer: contact and interface behavior a
 
 [[Abaqus-Analysis-User-s-Guide-Volume-V|Volume V]] expands contact into a complete modeling workflow: define general contact or contact pairs, assign surface and contact properties, select formulation and enforcement methods, inspect diagnostics, resolve modeling difficulties, and use Abaqus/Standard contact elements only for specialized cases.
 
+[[Midas-FEA-Analysis-Manual|Midas FEA Analysis Manual]] adds a search-and-penalty view: global bucket search, local master-surface search, Newton closest-point calculation, penetration-based penalty force, symmetric weld/general contact, and contact force output on slave surfaces.
+
+[[Midas-NFX-Analysis-Manual|Midas NFX Analysis Manual]] adds a broader contact set: general, rough, welded, sliding, breaking-weld, single-surface, node-to-surface, surface-to-surface, and mortar contact, with penalty normal force, friction limits, smoothed force transition, and contact-force based weld release.
+
 ## Why It Matters
 
 Contact is one of the common reasons a finite element problem becomes nonlinear. It can dominate convergence, mesh sensitivity, and physical response, especially in shell-to-solid interaction, impact, forming, bolted assemblies, and problems with changing boundary conditions.
@@ -71,6 +80,9 @@ Contact is one of the common reasons a finite element problem becomes nonlinear.
 - [[Abaqus Contact Interaction Definition]], [[Abaqus Contact Property Models]], and [[Abaqus Contact Formulations and Enforcement]] split the Abaqus contact workflow into definition, behavior, and numerical enforcement.
 - [[Abaqus Contact Diagnostics and Modeling Difficulties]] covers initial overclosures, surface quality, redundant constraints, and other contact failure modes.
 - [[Abaqus Connector Elements and Behaviors]] and [[Abaqus Cohesive and Gasket Elements]] cover element-based interaction alternatives.
+- [[Midas FEA Static Contact Analysis]] describes contact search and penalty enforcement in Midas.
+- [[Midas FEA Interface Elements and Nonlinearities]] covers predefined interface elements and nonlinear interface laws.
+- [[Midas NFX Contact Analysis]] describes NFX penalty contact, mortar contact, friction, and breaking-weld behavior.
 
 ## Sources
 
@@ -78,3 +90,5 @@ Contact is one of the common reasons a finite element problem becomes nonlinear.
 - [[Abaqus-Analysis-User-s-Guide-Volume-I|Abaqus Analysis User's Guide Volume I]]
 - [[Abaqus-Analysis-User-s-Guide-Volume-IV|Abaqus Analysis User's Guide Volume IV]]
 - [[Abaqus-Analysis-User-s-Guide-Volume-V|Abaqus Analysis User's Guide Volume V]]
+- [[Midas-FEA-Analysis-Manual|Midas FEA Analysis Manual]]
+- [[Midas-NFX-Analysis-Manual|Midas NFX Analysis Manual]]