Investigation of the effect of moisture on the critical parameters of stability of frame-rod structural systems made of wood

Abstract

The work of end moments and shear forces is taken as a criterion influencing the value of the limiting compressive force. It was found that the form of bifurcation of an individual element (active or passive) has a significant effect on the value of the critical parameters of stability of the entire system as a whole. A frame-rod structural system made of wood is considered. The influence of humidity on the type of bifurcation of its compressed elements (constrained or forced) and the critical parameters of stability of the system as a whole under various modes of force loading are determined. It is shown that with a change in humidity, individual elements can go from passive loss of stability to active, which will change the value of the critical force by an average of 20 %. To check the obtained analytical dependencies, experimental tests of frame-bar structures made of wood were carried out under their power static loading and variable humidity. At the same time, it was noted that the results of numerical and laboratory studies showed satisfactory agreement, on average by 95 %, which indicates the reliability of the developed methodology.