Determination of maximum support moments and their dependences in statically indeterminate rods subjected to a zero-cycle temperature change

Objective: to calculate and analyze sectional stresses and internal forces in the simplest statically indeterminate rods under cyclic temperature changes. Methods: two confi of rod comprising the basic system employed in the displacement method were considered. The fi confi featured one rigidly fi end and a hinged, movable support at the opposite end; its direct analogue was a rod with a longitudinally sliding fastening at one end and a fi hinge at the other. The second confi involved a rigid fi end combined with a sliding fastening at the opposite end. Both confi were investigated under a non-zero temperature change cycle. In addition to stresses, the study determined the peak internal forces – particularly bending moments – an outcome not observed for a statically determined rod. Results: the magnitudes of the maximum stresses and maximum moments converge to steady-state values as cycle time increases and the rod section height decreases. Maximum compressive stresses under cyclic thermal loading substantially exceed their steady-temperature values, reaching up to 35 % above them. Practical signifi the derived approximation functions for moment stresses can be employed in subsequent calculations of core systems. For improved accuracy, the obtained tabulated function values and linear interpolation between them should be used.