Define Materials
Assign a material to every body in Dr.Q, using the parameters it knows for standard materials or your own values.
If you only have 2 minutes
Assign a material to every solid body in your model. For standard materials Dr.Q already knows the parameters; otherwise you enter your own values. Either way, check the parameters against the material's datasheet.
Material parameters
You can define your own material or use a common material name. Dr.Q knows the relevant parameters for many common materials, so naming the material is often enough. Always check those parameters against the datasheet of the material you are using.
Custom materials
You can define custom materials by entering your own values for Young's modulus, Poisson's ratio, and density.
Make sure your material values are in consistent units. Dr.Q works in MPa (N/mm²) by default. A common mistake is entering Young's modulus in GPa, 210 GPa looks right but is 1000× too small in the MPa unit system.
Valid parameter ranges
Material inputs must be physically valid, or the solve can fail, often deep in the run rather than at input:
- Young's modulus (and the other moduli) must be positive.
- Poisson's ratio must be between -1 and 0.5; most metals are near 0.3.
An unphysical value, such as a negative modulus or a Poisson's ratio outside that range, can drive the shear modulus non-positive and abort a plasticity solve (see Material Problems).
Beyond linear elastic
Dr.Q also supports nonlinear material models:
- Plasticity: add a yield stress and a hardening definition. Below the yield stress the material is elastic; above it, it deforms permanently.
- Viscoelasticity: the response depends on time (creep and relaxation), so a viscoelastic material needs a time-dependent analysis (a time definition), not a static one.