Gasket Element
Gasket Element: Theoretical Foundations
What is a Gasket Element?
Professor, what is a gasket element?
Gasket element is a dedicated element for modeling the gasket (sealing material) between flanges. It represents the nonlinear hysteresis of compression-unloading of the gasket.
Characteristics of gaskets:
- Stiffness increases nonlinearly with compression — Load-displacement curve is convex upward
- Does not fully recover upon unloading — Plastic deformation (permanent strain)
- Hysteresis — Compression and unloading paths are different
- Behavior in the thickness direction is dominant — Weak in-plane
Implementation in FEM
Summary
ASME Pressure Vessel Code 1914
The standardization of industrial gasket design began with the establishment of the ASME Boiler and Pressure Vessel Code (BPVC) in 1914. The concepts of the gasket factor m (tightness factor) and y (minimum seating stress) are defined in ASME BPVC Section VIII Division 1. Even in modern FEM analysis, the experimental measurement of the in-situ pressure-displacement curve (closure curve) for gasket materials is conducted in accordance with this code.
Computational Methods for Gasket Element
Gasket Material Model
Gasket load-displacement characteristics are obtained from material testing. Test data from ASTM F36 (compressibility), F38 (creep relaxation).
Setting in Abaqus:
```
*GASKET BEHAVIOR, NAME=gasket_prop
*GASKET THICKNESS BEHAVIOR
0., 0.
0.5, 10.
1.0, 50.
1.5, 150.
```
Directly input the table of compression amount vs. contact pressure.
Summary
Formulation of Gasket Elements
The characteristic of dedicated gasket elements is the ability to independently define stiffness in the thickness direction (closure direction) and in-plane direction (membrane). In ABAQUS GK elements (Gasket element), closure behavior and transverse shear stiffness can be input via tables, allowing representation of different nonlinear behaviors on the compression and tension sides (e.g., exponential curve during compression, nearly zero stiffness during tension). This formulation is based on Ballard's (1994) ENGAS element, with Simula (now Dassault) completing the implementation.
Gasket Element in Practice
Gasket Practice
Leakage evaluation for pressure vessel flanges. In ASME BPVC Section VIII flange design, gasket contact pressure is critical.
Practical Checklist
Engine Head Gasket Analysis
Automotive engine head gasket analysis is one of the most mature fields of FEM application from the 2000s. In an analysis published by Honda in 2005, the three-layer structure of a metal gasket (MLS: Multi Layer Steel) was modeled using ABAQUS GK elements, achieving accuracy within ±10% compared to actual contact pressure distribution measured by the contact film method around the cylinder bore. This contributed to reducing prototype development cycles by 2 iterations compared to conventional methods.
Gasket Element: Software & Solver Comparison
Gasket Tools
Selection Guide
Implementation History of ABAQUS GK Elements
Dedicated gasket elements (GAXAn, GKnnn series) were added to ABAQUS in Version 5.8 (around 1998). Before that, approximation with nonlinear spring elements (SPRING2) was the only option. Standard implementation of gasket elements in Nastran was delayed, with the GASKET-PROPERTY card finally added in MSC Nastran 2012. Currently, GK elements are also available in NX Nastran's nonlinear solvers (SOL 601/701).
Advanced Technology
Advanced Gasket Research
Related Topics
Experience the theory firsthand with the interactive simulator for this field
All Simulators