Stresses and Internal Forces Summary

This report provides maximum absolute envelope values of wall/diaphragm stresses and internal forces. It is important to note that reported values are maximum absolute values with their sign.

Results for walls can be generated with Reports > Stress and Internal Force Summary - Wall command. Similarly, Reports > Stress and Internal Force Summary > Diaphragm provides results for diaphragms.

For each wall, the report gives maximum values of stresses/internal forces found in entire wall. Note that reported values for each stress/internal force type may not be occurring at the same location. (for instance, FMax and FMin may not be at the same location within the same wall).

Similarly, the report gives maximum values of stresses/internal forces of each diaphragm (diaphragm is either semirigid or contains two-way deck). Again, reported values for each stress/internal force type may not be at the same location in entire diaphragm.

In the tables below, reported stresses/internal forces are explained in detail. Note that these maximum values are obtained by reviewing those calculated in all shell elements (located in a wall or diaphragm). In other words, they are not maximum values averaged at nodes. In order to see these values on screen, unselect Stress Averaging and select Show Stress contour values options in the Stress and Internal Force Contours dialog.

The report lists stresses at top\positive and bottom\negative faces separately.

Table 1. Internal Forces: Membrane force (force per unit of in-plane length)
FMax	Maximum principal normal force acting at mid-surface¹
FMin	Minimum principal normal force acting at mid-surface¹
Von Mises	Von Mises principal force²
MMax	Maximum principal moment force acting at mid-surface¹
MMin	Minimum principal moment force acting at mid-surface¹
VMax	Maximum principal shear¹

Principal normal forces are oriented in such a way that associated shearing force is zero.
Von Mises principal force is calculated as follows:
$F_{V M} = \sqrt{F_{M a x}^{2} - F_{M a x} F_{m i n} + F_{M i n}^{2}}$
where
$F_{M a x}$ , $F_{m i n}$
=
principal maximum and minimum normal forces, respectively
Principal moments are oriented in such a way that associated twisting moment is zero.
Maximum principal shear is calculated as follows:
$V_{M a x} = \sqrt{V_{13}^{2} + V_{23}^{2}}$
where
$V_{13}$ , $V_{23}$
=
out-of-plane shears, respectively

Table 2. Stresses: In-Plane (force per unit area)

SMax	Maximum principal normal stress ¹
SMin	Minimum principal normal stress ¹
SVmax	Maximum principal shear stress ²
Von Mises	Von Mises principal stress ³
SAvgMax	Maximum out-of-plane shear stress¹

Principal normal stresses are oriented in such a way that associated shearing stress is zero.
Maximum principal shear stress is calculated as follows:
${S V}_{m a x} = A b s |\frac{S_{M a x} - S_{m i n}}{2}|$
where
$S_{M a x}$ , $S_{m i n}$
=
principal maximum and minimum normal stresses, respectively
Von Mises principal stress is calculated as follows:
$S_{V M} = \sqrt{S_{M a x}^{2} - S_{M a x} S_{m i n} + S_{M i n}^{2}}$
where
$S_{M a x}$ , $S_{m i n}$
=
principal maximum and minimum normal stresses, respectively
Maximum out-of-plane shear stress is calculated as follows:
$S_{V M} = \sqrt{S_{13}^{2} + S_{23}^{2}}$
where
$S_{13}$ , $S_{23}$
=

out-of-plane stresses in the direction of axis on face 1 and 2, respectively.