Alexander Korotkov

Simulation of orthotropic materials

Discussion created by Alexander Korotkov on Nov 10, 2020
Hi there,
I am trying to run a simulation (static analysis) of a pine structure in SW2020 Simulation Premium. Being unable to find any comprehensive tutorial on simulation of wooden structures (or orthotropic materials in general), I quickly faced several issues.
  1. Wood is an orthotropic material and thus the number of material properties the simulation engine asks triples. I.e., "Elastic Molulus" becomes "Elastic Modulus in X", "Elastic Modulus in Y", and "Elastic Modulus in Z". The same goes for "Poisson's Ratio" (i.e., XY, YZ, XZ). As some noticed before, Solidworks' materials database leaves much to be desired. No wood materials with orthotropic model type can be found there. Hence, I have to add all material properties myself.
    "Elastic Modulus" and "Poisson's Ratio" are relatively easy to get and can be sourced from Forest Products Laboratory "Wood Handbook" (see, for example, PDF here, pp. 5-2, 5-3, 5-7, 5-8).
    The hard thing is a "Yield Strength", that is necessary for FoS analysis. I failed to find any reliable data on "Yield Strength" for any wood material. MatWeb gives some data, but which of those metrics (two numbers on "Flexural Yield Strength" and 4 numbers on "Compressive Yield Strength") correspond to SW's only "Yield Strength"? Furthermore, in SW, there is only one text field for "Yield Strength". I.e. "Yield Strength" is assumed to be identical along all axes, which seems unreliable. Thus, my first couple of questions are:
    1.1. Is "Yield Strength" for wood material really a single number, equal along all three axes?
    1.2. What is the reliable source of data on "Yield Strength" for wood materials to use in SW simulation?
  2. Assume the above issues are settled. With orthotropic materials, one has to define "Reference geometry", i.e. explain to SW, how coordinate system is aligned with regard to the three principal axes of wood -- longitudinal, radial, and tangential. This is quite easy in the case of simulation of a simple wooden part. But what if I have an assembly consisting of several wooden parts that are aligned differently with regard to each other? Should "Reference geometry" be set separately for each part? At what stage? Thus, my question here:
    2. How would I set "Reference geometry" for parts in the case of a wooden assembly?
  3. Is SW really an appropriate software for simulation of wooden structures? What software is used by IKEA, for example, to simulate its furniture? Thus, my last question is:
    3. If it's not SW, what is the software of choice for simulation of wooden structures?
I would be highly grateful for your help,
Kind regards
Just in case, posts I am already familiar with: