TY - RPRT

T1 - Vridningsstivhed beregnet vha. statisk tilladelige
spændingsfordelinger

T2 - (Torsional stiffness calculated by means of statically
admissible stress fields)

AU - Christiansen, Morten Bo

AU - Nielsen, Mogens Peter

PY - 1996

Y1 - 1996

N2 - The present report shortly describes the theory of calculation of
torsion stiffness by means of the energy equation applied to
statically admissible stress fields. Moreover it describes an easy
way of determining these stress fields by means of Prandtl's
stress function.The calculations are carried through for two solid
cross-sections, a square and a rectangular one. Different
solutions are suggested, and comparison with the exact solution is
made. The comparison shows that even with very simple assumptions
about the stress field, fairly accurate approximations to the
torsion stiffness (lower bound values) can be achieved. The best
solution for the rectangular cross-section has a maximum deviation
from the exact solution of 11%. This solution also provides an
acceptable approximation to the maximum shear-stress. The
deviation from the exact maximum stress is 17%.

AB - The present report shortly describes the theory of calculation of
torsion stiffness by means of the energy equation applied to
statically admissible stress fields. Moreover it describes an easy
way of determining these stress fields by means of Prandtl's
stress function.The calculations are carried through for two solid
cross-sections, a square and a rectangular one. Different
solutions are suggested, and comparison with the exact solution is
made. The comparison shows that even with very simple assumptions
about the stress field, fairly accurate approximations to the
torsion stiffness (lower bound values) can be achieved. The best
solution for the rectangular cross-section has a maximum deviation
from the exact solution of 11%. This solution also provides an
acceptable approximation to the maximum shear-stress. The
deviation from the exact maximum stress is 17%.

M3 - Rapport

BT - Vridningsstivhed beregnet vha. statisk tilladelige
spændingsfordelinger

ER -