EXPERIMENTAL INVESTIGATION OF BOLTED TIMBER CONNECTIONS WITH STEEL PLATES

Abstract

 Currently, the use of timber building structures has gained great popularity in the 
world. The appearance of modern types and technologies for the manufacturing of joints of timber 
structures elements makes it necessary to conduct corresponding studies of its behaviour under load, 
as well as theoretical and experimental assessment of load-bearing capacity and deformability. 
The article presents the results of theoretical and experimental studies of the performance of 
the bolted connection of glued timber elements with metal plates under the action of a tensile load 
parallel to the fibers. 
A  sample  consisting  of  a  glued  timber  beam  750  mm  long  with  cross-section  section 
dimensions of 120x120 mm and a connecting steel plate embedded in a solid wood was adopted for 
the study. The joint work of the beam and the plate is ensured by three bolts with a diameter of 
12 mm. Glued laminated timber is made of pine wood lumber. 
The technique for the experiment was developed. As a result of the tests, the actual value of 
the  failure  load equal to 113.7 kN was obtained, as well as a diagram of the dependence of the 
deformation of the sample on the magnitude of the tensile load. The behaviour of the sample under 
a load up to 80 kN is characterized by a close to linear dependence. At larger values of the load, 
nonlinear  deformations  occur  due  to  the  bending  of  the  bolts.  An  analysis  of  the  shape  of  the 
bending  of  the  bolts  allows  suggesting  the  uniform  redistribution  of  the  inner  forces  of  the 
connection. 
Taking into account the current design standards, the theoretical bearing capacity of the joint 
was  determined  according  to  the  possible  forms  of  failure.  The  experimental  value  differs  from 
theoretical  by  67.5%  and  11.3%,  respectively.  It  is  established  that  the  main  parameter  that  has 
determined the bearing capacity of the connection is the embedment strength of the wood under the 
surface of the bolt.