Stiffness Analysis of Connections of LVL Structures with Claw Washers
Journal Title: Lesnoy Zhurnal (Russian Forestry Journal) - Year 2020, Vol 11, Issue 4
Abstract
The use of claw washers in dowel connections allows to increase the bearing capacity and stiffness of joints. However, joint action of claw washers and dowels in the structures of advanced materials is studied insufficiently. The paper presents the key failures of existing methods for calculating such connections. Differential equations, that simulate the behavior of a dowel connection with claw washers taking into account the possible changes in the shape of claws, wood moisture content and the duration of loading, are presented. Washer dowel and claw are followed the equations for beams secured on a visco-elastic base, using the equation kernel K(τ,t), which reflects the nonlinearity of the factors affecting the deformation of a connection. The dowel deformation equations are given, which are proposed to be solved by the Bubnov-Galerkin method. The obtained expressions are united into a single equation using the Heaviside step functions. The deformation equations are presented as well. They are written taking into account the virtual displacement of a claw in two orthogonal directions. The expressions allow to pass from calculation of washer claws and a dowel to determination the total bearing capacity and joint stiffness. The possibility of plastification due to the changes in boundary conditions is considered for adequate simulation of connection components behavior upon reaching the plastic stage. The article provides a methodology for determining the theoretical displacements and linear stiffness of a connection. The equations are calculated using dependences available from experiments. In the course of solving the equations, it is possible to determine the values of linear stiffness. These values are compared with the experimental data received earlier to assess the adequacy of the obtained solutions. The distribution of theoretical and experimental data have an average convergence of 91 %, which confirms the validity of the presented methodology for determining the stiffness of dowel connections in LVL with claw washers. The proposed methodology can be recommended for more precise calculation of wooden structures in strength and stiffness, which will reduce their material consumption and enhence reliability.
Authors and Affiliations
A. G. Chernykh, E. V. Danilov, P. S. Koval
Keywords
Related Articles
- EP ID EP688517
- DOI 10.37482/0536-1036-2020-4-157-167
- Views 200
- Downloads 0
Efficiency of Thinning in Deciduous-Spruce Forest Stands in the Northern Taiga Forest Region of the European Part of the Russian Federation
Research on permanent sample plots (Arkhangelsk, Northern district forestry, Obozerskoye forestry) in birch and spruce stands with an understory layer of spruce was carried out. The sample plots were established since 19...
Influence of Growth Stimulants on Seed Germination and Seedlings Growth of Scots Pine (Pinus sylvestris L.)
Scots pine (Pinus sylvestris L.) is a potential introduced plant that can be used for reforestation in the southern part of Primorsky Krai. This plant is valuable for water regulation and mountain strengthening. It is wi...
Contact Interaction of a Claw Washer with Wood at Limiting Shear
When designing, manufacturing and maintaining of woodworks and elements of wooden structures it is necessary to solve the problem of providing the calculation of strength, stiffness and their bearing capacity. This probl...
Differentiation of Dust Holding Capacity of Poplar Crowns
One of the key parameters of comfort and compliance with sanitary standards for cities is dustiness of atmosphere. Plantings of representatives of the poplar genus (Populus L.) become a reliable means of optimizing this...
Modeling the Process of Sawn Timber Drying
The article considers the problem of sawn timber drying. The relevance of research is driven by the need to improve the automated process control system for drying sawn timber on the basis of modern information technolog...