Model

The model block defines the physics, the material assignment, and optional field-recovery and mesh-quality settings. For a solid-mechanics simulation the type is solid mechanics:

model:
  type: solid mechanics
  material:
    blocks:
      body: steel
    steel:
      model: linear elastic
      elastic modulus: 6.895e+09
      Poisson's ratio: 0.25
      density: 2768.0

`type`

Required string. Selects the model. For full-order solid mechanics use solid mechanics. The value mesh smoothing runs the mesh-smoothing model (and implicitly enables the mesh smoothing option below). The reduced-order model types are documented separately with the norma-opinf companion package and are outside the scope of this guide.

`material`

Required. Assigns a constitutive model to each mesh element block. See Materials for the full specification of blocks and the per-material parameters.

Integration points

Key	Required	Default	Meaning
`num integration points`	no	element default	map of element-block name → integer quadrature-point count, overriding the default rule for that block

model:
  type: solid mechanics
  num integration points:
    body: 8
  material:
    ...

Nodal recovery

Optional. Enables L2-projection recovery of element quantities to the nodes for output. Omitting the block disables recovery.

Key	Required	Default	Values / meaning
`method`	yes (if block present)	—	`lumped`, `consistent`, or `both` (projection mass matrix)
`stress`	no	`true`	recover the stress tensor
`von mises stress`	no	`false`	recover the von Mises stress
`internal variables`	no	`false`	recover material internal variables
`deformation gradient`	no	`false`	recover the deformation gradient

model:
  type: solid mechanics
  nodal recovery:
    method: lumped
    stress: true
    von mises stress: true
  material:
    ...

The legacy keys stress recovery and recover internal variables are no longer accepted and cause an error; use the nodal recovery block above.

Mesh smoothing

Key	Required	Default	Meaning
`mesh smoothing`	no	`false`	enable mesh smoothing (set automatically when `type: mesh smoothing`); a top-level key
`smooth reference`	no	`""`	reference-metric rule for TETRA4 smoothing: `equal volume`, `average edge length`, `max`, `size field`, or `size field unrestricted`
`size field`	required if `smooth reference: size field`/`size field unrestricted`	`nothing`	expression in `t, x, y, z` giving the target element size

Mesh smoothing is a specialized capability; most simulations omit these keys. See examples/ems/ for smoothing cases.

Canonical examples

Basic model/material block: examples/single/static-solid
Mesh smoothing: examples/ems/cube/cube.yaml