Means and standard deviations of grade determining properties (GDPs) from literature
gdp_dataWood species as a four letter code according to EN 13556. Currently, this is always "PCAB" for Norway spruce (Picea abies).
Kind of destructive testing applied to the material -- "t" for material tested in tension, "be" for material tested in bending.
Research project from which the data originated; "null"
if unknown or not applicable.
Country from which the material originated, as a two letter country code.
Number of pieces on which the values are based.
Mean and standard deviation of strength, in N/mm².
Mean and standard deviation of the static modulus of elasticity, in N/mm².
Mean and standard deviation of density, in kg/m³.
Reference to the literature source; "null" if not
published yet.
For distinguishing multiple rows with the same species,
loadtype and country -- if there are no duplicates, it is the same as
country; if there are duplicates, it is country plus a
suffixed number separated by "_".
For simulation of an entire dataset with different subsamples with different
characteristics (see simulate_dataset()),
it may be useful to be able to refer to existing results
from literature as a basis.
In the dataset gdp_data, means and standard deviations for a number of
such subsamples have been collected.
The GDP values collected in gdp_data were selected from
publications which aimed at representative sampling within the respective
countries.
All the same, care must be taken when using these values,
due to the natural high variability of timber properties.