These local notes derive linear isoparametric solid elements for three-dimensional continuum modeling. They cover nodal displacement interpolation, common first-order solid element topologies, natural-coordinate shape functions, the strain-displacement matrix, Hooke-law material stiffness, Gaussian integration for element stiffness, and incompatible modes for locking relief.
The local source is a converted Markdown/image extraction: one Markdown file and 65 extracted images under .raw/SolidElement/.
Linear solid elements model three-dimensional volume response with three translational degrees of freedom per node and no rotational degrees of freedom.
The same shape functions interpolate both geometry and displacement, making the notes a direct extension of Isoparametric Finite Elements into 3D continuum elements.
The Jacobian maps derivatives from natural coordinates to physical coordinates, allowing the B matrix to be assembled in global coordinates.
The element stiffness follows the standard displacement-based form K = integral B^T D B dV, evaluated in natural coordinates with the Jacobian determinant.
Incompatible modes add internal displacement modes to selected wedge and hexahedral elements, then eliminate those extra degrees of freedom by static condensation.
Composite source hash recorded in .raw/.manifest.json.
The note contains a few OCR/math transcription issues in the quadrature expressions, but the formulation sequence and element topology coverage are usable.
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