Allowable principal stresses
Handling with the function is analogous to Checking of limit strain. The values offered for display are naturally different.
Values
|
Sigma 1 |
self-explanatory (see also Detailed check of allowable principal stresses) |
|
Sigma 2 max |
self-explanatory (see also Detailed check of allowable principal stresses) |
|
Sigma 3 max |
self-explanatory (see also Detailed check of allowable principal stresses) |
|
Sigma x max |
self-explanatory (see also Detailed check of allowable principal stresses) |
|
Sigma y max |
self-explanatory (see also Detailed check of allowable principal stresses) |
|
Sigma z max |
self-explanatory (see also Detailed check of allowable principal stresses) |
|
Tau xy max |
self-explanatory (see also Detailed check of allowable principal stresses) |
|
Tau xz max |
self-explanatory (see also Detailed check of allowable principal stresses) |
For the procedure read Performing the check of allowable principal stresses.
Allowable principal stresses according to NEN 6720
Theory
The value σ1 is calculated according to chapter 8.2.3.3 of NEN 6720
The most general method of the evaluation of principal stresses in the 3D beam member has been implemented in the program.
Where:
σ1,2,3 principal stresses
σ'bd = σx concrete compressive stress in axis x
σy,z concrete compressive stress in axis z
τd = τxz concrete shear stress in plane xz
Results:
σ1 ≤ fb → OK, The cross-section satisfies
σ1 > fb → NOT OK, The principal stresses are greater than the allowed stress
Where fb is design tensile strength of concrete
fb = 0.7∙(1.05+0.05∙fck)/1.4