scholarly journals Strengthening of the wooden structures

2020 ◽  
Vol 18 (3) ◽  
pp. 017-028
Author(s):  
Szymon Ślósarz
Keyword(s):  
Composite Materials ◽  
Bearing Capacity ◽  
Operating Conditions ◽  
Review Of The Literature ◽  
Wood Degradation ◽  
Load Bearing Capacity ◽  
Traditional Methods ◽  
Load Bearing ◽  
Modern Methods ◽  
Wooden Structures

The paper is a review of the literature on the strengthening of wooden structures. The strengthening methods are classified according to their purpose and specifics. The article deals with both traditional methods commonly used and modern methods involving the use of composite materials. The paper also includes description of studies on various strengthening methods as well as the presentation of their results. The author also refers to the causes of the loss of load bearing capacity, causes of wood degradation and wooden structures durability in relation to operating conditions.

scholarly journals Determination of the load-bearing capacity of «steel-wood» connections of LVL structures under tension

2021 ◽  
Vol 18 (1) ◽  
pp. 60-69
Author(s):  
Quoc Phong Tran ◽  
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Steel Plate ◽  
Experimental Studies ◽  
Steel Plates ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Dowel Connections ◽  
Wooden Structures

The article presents the results of calculation of the load-bearing capacity of connections of LVL structures under tension using cylindrical dowels in trusses and frames. The description of calculation schemes for determining the load-bearing capacity of connections with different location and sizes of steel plates in the connection is given. The influence of steel plate placement on the distribution of forces in the cross-section of samples is investigated. Based on the results of analytical and experimental studies, the load-bearing capacity of dowels during bending is considered, as well as the mechanism of wooden structures` fracture during chipping. A comparative analysis of the effectiveness of different schemes of dowel connections with three steel plates under tension is carried out.

ENGINEERING PROCEDURE FOR EVALUATING THE LOAD-BEARING CAPACITY AND LIFE OF A DEFECTIVE STRUCTURE

2020 ◽  
pp. 36-49
Author(s):  
Aleksey N. SOFINSKIY
Keyword(s):  
Fracture Mechanics ◽  
Bearing Capacity ◽  
Material Properties ◽  
Operating Conditions ◽  
Engineering Practice ◽  
Stress Strain ◽  
Load Bearing Capacity ◽  
Defective Structure ◽  
Load Bearing ◽  
Manufacturing Defects

A piece of rocket and space hardware may consist of tens of thousands of parts. Virtually every as-built piece of hardware has some non-conformances to the design documentation. Manufacturing defects often occur or are discovered during the final stages of the vehicle assembly or pre-launch processing. In such cases, removal of the non-conformance is either impossible or is too difficult and costly. The procedure described in the paper makes it possible to evaluate the degree of impact of a typical defect on the load-bearing capacity, strength, leak integrity, and life of a structure under its operating conditions. Sections of the procedure include description of operations involving non-destructive testing, determining loads on the vehicle and other operating conditions, stress-strain analysis, experimental determination of the material properties, prediction of the crack kinetics from the standpoint of fracture mechanics. The procedure gives a structural analyst an algorithm for solving the complex problem of estimating the service life, which consists of a sequence of specific tasks: developing the finite element model, classifying the defect, constructing the loading block, analyzing stress-strain behavior, predicting the behavior of the initial defect. Introducing the procedure into engineering practice will make it possible to increase validity of the estimate of the load bearing capacity and life, and, therefore, of the reliability and safety of the vehicle operation. Key words: structure, defect, crack, loads, stress condition, material properties, fracture mechanics, strength, leak integrity, life.

scholarly journals Rotational Stiffness and Carrying Capacity of Timber Frame Corners with Dowel Type Connections

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7429
Author(s):  
Marek Johanides ◽  
David Mikolasek ◽  
Antonin Lokaj ◽  
Petr Mynarcik ◽  
Zuzana Marcalikova ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Experimental Test ◽  
Carrying Capacity ◽  
Rotational Stiffness ◽  
Load Bearing Capacity ◽  
Computational Approaches ◽  
Load Bearing ◽  
Timber Frame ◽  
Numerical Tests ◽  
Wooden Structures

With the development of wooden structures and buildings, there is a need to research physical and numerical tests of wood-based structures. The presented research is focused on construction and computational approaches for new types of joints to use in wooden structures, particularly glued lamella elements made of wood and wood-based composites. This article focuses on improving the frame connection of a wooden post and a beam with the use of fasteners to ensure better load-bearing capacity and stiffness of the structure. In common practice, bolts or a combination of bolts and pins are used for this type of connection. The aim is to replace these commonly used fasteners with modern ones, namely full thread screws. The aim is also to shorten and simplify the assembly time in order to improve the load-bearing capacity and rigidity of this type of frame connection. Two variations of the experimental test were tested in this research. The first contained bolts and pins as connecting means and the second contained the connecting means of a full threaded screw. Each experiment contained a total of two tests. For a detailed study of the problem, we used a 2D or 3D computational model that models individual components, including fasteners.

scholarly journals Analysis of various failure models of steel-wood connections with self-drilling dowels

2020 ◽  
Vol 17 (5) ◽  
pp. 72-81
Author(s):  
Quoc Phong Tran ◽  
Keyword(s):  
Bearing Capacity ◽  
Brittle Failure ◽  
Large Diameter ◽  
Small Diameter ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Failure Propagation ◽  
Failure Models ◽  
Dowel Connections ◽  
Wooden Structures

The load-bearing capacity of the dowel connections of wooden structures is determined by two limiting states, namely, by the failure of wood (crumpling) or deformation of steel dowel (bending). Both failure models are plastic. In some cases, brittle failure is possible, which will determine the load-bearing capacity of the connection. However, the regulations in the Russian Federation do not consider the brittle failure of dowel connections because this type of failure is excluded by the rules for placing dowels. Appendix A of Eurocode 5 includes types of brittle failure caused by chipping of a block or slipping of wood in connection. In [10, 11], the authors consider various fracture models for connections with large-diameter dowels (over 12 mm). In the present study, the author evaluates and classifies calculation models for brittle failure in connections of wooden structures using self-drilling dowels of small diameter (less than 12 mm), which are not presented in the Eurocode 5 and SP 64.13330.2017 standards. Solutions are proposed for reducing the probability of brittle failure propagation in such connections.

scholarly journals Development of improved models for pile load bearing capacity, settlement and reliability analysis

Vestnik MGSU ◽  
2020 ◽  
pp. 789-823
Author(s):  
Vladimir S. Utkin ◽  
Sergey A. Solovyev
Keyword(s):  
Bearing Capacity ◽  
Operating Conditions ◽  
Performance Criteria ◽  
Pile Foundations ◽  
Load Bearing Capacity ◽  
Foundation Soil ◽  
Important Indicator ◽  
Reliable Determination ◽  
Load Bearing ◽  
Pile Settlement

Introduction. Safety of operation and durability of pile foundations and structures as a whole depend on the values of load bearing capacity of piles and reliability in the foundation soils. The key problem of pile analysis consists in reliable determination of its load bearing capacity values according to all performance criteria of the first and second groups of limit states, in revealing of reliable values of reliability (operation safety), economic efficiency and profitability. Materials and methods. One of the difficulties in detecting the value of the load bearing capacity of friction piles is to determine the values of friction and cohesive forces and their distribution over the side surface of the pile in the foundation soil when the loaded pile is immobilized (at rest). Results. Absence of reliable information on actual friction and cohesive force and, consequently, on actual load bearing capacity of a pile in the conditions of immobility does not allow to estimate its quality taking into account assurance of trouble-free operation (reliability) in real operating conditions at the pre-set operating load, it is impossible to predict the durability of a pile, to make a reasonable choice of pile shape and dimensions, etc. Another pile analysis problem is determining the value of pile settlement. The value of pile settlement is in some cases the most important indicator of the facility performance. Conclusions. New approaches to the operation of piles in the foundation soil on the basis of modern methods of reliability calculations with limited statistical information about controlled parameters are proposed. Improvement and development of pile calculation methods can be found in the calculation of deep trencher foundations, in the calculation of open caissons and caissons, the development of new statutory documents on pile foundations; as well as during training process of various universities and as a source for advanced training of specialists.

Study on Strengthening Glued-Laminated Timber with Aramid Cords and Properties of Composite Materials

2012 ◽  
Vol 583 ◽  
pp. 142-145 ◽  
Author(s):  
Marlena Rajczyk ◽  
Damian Jończyk
Keyword(s):  
Composite Materials ◽  
Numerical Analysis ◽  
Bearing Capacity ◽  
Normal Stress ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Reinforced Beams ◽  
Glued Laminated Timber

This paper presents method of strengthening glued-laminated timber with aramid cords. In order to estimate the increase in load-bearing capacity, numerical analysis was carried out on three beams: unreinforced; reinforced with one layer of aramid cords; and reinforced with two layers of aramid cords. A preliminary numerical analysis showed a reduction of deflections of reinforced beams by about 11 to 14 % and a reduction of 19 to 25 % of normal stress.

scholarly journals Analysis of the load bearing capacity of the connection with the use of self-drilling dowels in various models of elastic failure

2020 ◽  
Vol 17 (4) ◽  
pp. 89-99
Author(s):  
A. G. Chernykh ◽  
◽  
Quoc Phong Tran ◽  
Keyword(s):  
Bearing Capacity ◽  
High Strength ◽  
Steel Plates ◽  
Use Of Self ◽  
Calculation Methods ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Factors Affecting ◽  
Wooden Structures ◽  
The Relationship

Currently, wooden structures characterized with high strength, low deformability and good aesthetics are being increasingly used in some areas of construction. Connections with multiple steel plates are very effective for wooden frames and trusses. In order to provide optimal connections, it is necessary to establish the relationship between the connection parameters and the load-bearing capacity of the structure. However, the technical regulations do not provide calculation methods specifically for this type of connection. There have been carried out a research and development of methods for calculating connections, an analysis of the self-drilling dowels` performance, and the factors affecting the load bearing capacity according to Eurocode 5 have been specified. The results obtained have been compared with other various research methods` results, there are offered authors` recommendations on the application of the standard in Russia.

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