EXPERIMENTAL RESEARCH OF WOOD NOG CONNECTION IN HOLES UNDER THE ACTION OF SINGLE LOAD

Abstract

The results of experimental research  of the working of bolt joints due to  the effort of single static loads submitted in the article. Experimental research of symmetrical bolt joints with the ratio of the thickness of the planks    and ratio rating  .

On the base of the results of joint deformation of connected planks measurements and the average value of the deformation of the bolts, complete deformation diagrams were constructed.

For deformation measurements of mutual displacement of the elements of dowel joints, as well as the shear of bolts bending of all series were used by clock indicators CI-10i with scale interval 0.01 mm, which were fixed on opposite sides of the connections. After considering the results of the joint deformation measurements and the average value of the bolt deformation, new complete deformation diagrams were built.

The deformations of the bed of wood in the area of contact with the dowel under the bolt of the middle plank of connection were determined by the difference                . 

Diagram of wood deformation under the load   ()  in the dowel-middle plank contact area, the middle plank of the tim-plate symmetrical joint from the beginning of application of loading and to destruction has a curvilinear character similar to the diagram of deformation of wood by the action of compression along the fibers.  The diagram of the deformation of wood under the load in the area of contact with the center of the middle plank of the two-fold symmetrical connection are shown two different sections. The first section is the upward curve from the beginning of loading to the maximum values of loads, and the second one is the descending one.