Bearing capacity and deformability of joints of wooden elements on metal plates using screwed and glued screws
Abstract
Bearing capacity and deformability of joints of wooden elements on metal plates using screwed and glued screws
Incoming article date: 28.12.2021The article presents the results of comparative tests of samples of connections of wooden elements from glued wood on metal linings using screwed and glued screws, 3 samples of each of 5 types of connections (one glueless and four varieties of glued screwed connection). It has been established that the use of epoxy adhesives increases the strength characteristics of the adhesive-free joint by the criterion of breaking load by 1.46, 1.78, 1.70, 1.59 times, by the criterion of the elastic work of the joint by 1.56, 1.56, 1.82, 1.30 times for glued joints (ED-20 + PEPA, ED -20 + THETA, DER-331 + PEPA, DER-331 + THETA) respectively. Of the glued-in samples, the deformation Dult=2mm was achieved only by samples No. 8 (ED-20 + TETA) and No. 14 (DER-331 + TETA) at loads 1.77, 1.40 times greater than the load in a glueless joint. Full deformations Dp at the same load within the limits of elastic work of joints decrease by 7, 10.61, 10.61 times for glued joints (ED-20 + PEPA, ED-20 + TETA, DER-331 + PEPA), respectively. For samples of compounds (DER-331 + TETA) with a compared load value, the deformations are equal to 0.
Keywords: glued wood, metal linings, testing of joint samples, bearing capacity of the joint, deformability of the joint, upper limit of the elastic work region (URL), total deformation, permanent deformation, elastic deformation, safety factor