Experimental and theoretical studies into the stress-strain state of the purlin supported by sandwich panels

The article describes a developed technique of a numerical simulation of the stress-strain state of complex-reinforced elements, which allows you to create models of double-span continuous. The performed experimental and theoretical studies allowed us to carry out the testing of the developed design model and to justify the reliability of the proposed numerical simulation methodology. The results of the experimental studies were compared with those of the theoretical studies. The theoretical calculus algorithm was developed by using the finite element method. Theoretical calculations were performed by using the mathematical-graphical environment software system LIRA-SOFT and the mathematical and computer program MATLAB. On the basis of the experimental research, the iso-fields of displacements and stresses in the materials of an eccentrically compressed beam with a small bend of the slab were constructed, which collapse behind the inclined narrow strip of concrete and displacements and stresses in the materials of the eccentrically stretched beam, which is destroyed due to the yield of the upper mounting armature.

Download Full-text

Transport systems load-bearing structures state diagnistics and monitoring

Modern Transportation Systems and Technologies ◽

10.17816/transsyst20217443-51 ◽

2021 ◽

Vol 7 (4) ◽

pp. 43-51

Author(s):

Andrey N. Yashnov ◽

Lyubov A. Vasilchuk ◽

Pavel Yu. Kuzmenkov ◽

Ivan V. Chaplin

Keyword(s):

Strain State ◽

Natural Vibration ◽

Operational Reliability ◽

Transport Systems ◽

Vibration Frequencies ◽

Stress Strain ◽

Load Bearing ◽

Stress Strain State ◽

And Control ◽

Experimental And Theoretical Studies

Aim: To provide the study and control of the stress-strain state of load-bearing structures during the operation of magnetolevitation transport systems. Methods: Experimental and theoretical studies of dynamic parameters. Results: To assess the stress-strain state of the main load-bearing structures of magnetolevitation transport systems using string superstructure it is proposed to measure the natural vibration frequencies. Conclusion: The organization of diagnostics or monitoring of changes in the natural vibration frequencies of load-bearing structures ensures the operational reliability of load-bearing structures for Maglev.

Download Full-text

Experimental studies of the stress-strain state of reinforced concrete structures strengthened by prestressed basalt-composite rebar

Structural Mechanics of Engineering Constructions and Buildings ◽

10.22363/1815-5235-2021-17-3-288-298 ◽

2021 ◽

Vol 17 (3) ◽

pp. 288-298

Author(s):

Oleg D. Rubin ◽

Sergey E. Lisichkin ◽

Oksana V. Zyuzina

Keyword(s):

Reinforced Concrete ◽

Strain State ◽

Concrete Structures ◽

Hydraulic Structures ◽

Reinforced Concrete Structures ◽

Theoretical Studies ◽

Stress Strain ◽

Stress Strain State ◽

Internal Forces ◽

Construction Joints

Relevance. In recent years, composite materials have become widespread in the construction of reinforced concrete structures for industrial, civil and transport structures. It is proposed to strengthen the reinforced concrete structures of hydraulic structures with prestressed basalt composite rebar. It took an experimental and theoretical substantiation of technical solutions to strengthen the reinforced concrete structures of hydraulic structures with prestressed basalt composite reinforcement. The aim of the work was to carry out a set of experimental and theoretical studies of the stress-strain state and internal forces in low-reinforced concrete structures of hydraulic structures reinforced with prestressed basalt composite rebar. Methods. Experimental studies of the stress-strain state and internal forces were carried out on the basis of low-reinforced concrete beam-type models with interblock construction joints, harden with prestressed basalt composite reinforcement in the stretched (compressed) zones of the models. Theoretical studies of the stress-strain state and internal forces were carried out on the basis of the theory of reinforced concrete and structural mechanics. Results. As a result of the research carried out on typical low-reinforced concrete structures of hydraulic structures with interblock construction joints, the main stages of the stress-strain state of hydraulic reinforced concrete structures were formulated. Based on the data of experimental and theoretical studies, taking into account the reinforcement with prestressed basalt composite rebar, as well as with prestressed clamps in the shear zone, a method was developed for calculating the strength of low-reinforced hydrotechnical reinforced concrete structures with interblock construction joints.

Download Full-text

KNEE JOINT OF THREE-HINGED GLUED TIMBER PORTAL FRAME EXECUTED AS JOINT ON GLUED-IN RODS

Modern structures of metal and wood ◽

10.31650/2707-3068-2021-25-92-102 ◽

2021 ◽

pp. 82-102

Author(s):

А.Ya. Naichuk ◽

Keyword(s):

Knee Joint ◽

Software Package ◽

Strain State ◽

Experimental Studies ◽

Theory Of Elasticity ◽

Knee Joints ◽

Design Solution ◽

Stress Strain ◽

Stress Strain State ◽

Experimental And Theoretical Studies

In the modern construction of buildings and structures there are many constructive solutions for connecting the rafter with the column of wooden three-hinged portal frames. One of these constructive solutions is the use of knee joints executed as joint on glued-in rods. Despite the accumulated experience in the construction of buildings using timber structures with joints on glued-in rods, there are still urgent tasks to improve the technology of their manufacture and calculation models. The purpose of this work was to conduct experimental and theoretical studies of the knee joint executed as joint on glued-in rods to determine the stress-strain state of the timber in the connection region. To develop of proposals for improving knee joint executed as joint on glued-in rods. The study of the stress-strain state of the knee joint was carried out by solving a plane problem of the theory of elasticity using a software package based on the finite element method. In the software package used, procedures are implemented to take into account the anisotropy of the mechanical properties of wood, the violation of contact between the surfaces of the elements connected in the knee joint. Experimental studies were carried out by the method of static loading of a prototype of a knee joint made in full size, which in its geometric parameters and material properties corresponded to the CE model. As a result of the conducted studies, it was found that in the stretched zone of the knee joint, the glued rods of the rafter and the column are characterized by a significant uneven distribution of forces, in addition, the rods are subjected to compression, tension and bending. The most loaded are the rods located at the maximum distance from the joint of the rafter and the column. The distribution of forces in the rods of the compressed zone is close to uniform. The stress distribution along the length of the inclined rods of the embedded parts is characterized by a large unevenness. Based on the analysis of the stress-strain state of the knee joint of the frame, a new design solution is proposed in terms of the number of glued-in rods and their spacing.

Download Full-text

Theoretical studies of the stress-strain state of the elements of joints on glued washers

Journal of Physics Conference Series ◽

10.1088/1742-6596/2131/3/032094 ◽

2021 ◽

Vol 2131 (3) ◽

pp. 032094

Author(s):

M V Ariskin ◽

I V Vanin ◽

D O Martyshkin ◽

R T Iksanov

Keyword(s):

Computational Model ◽

Strain State ◽

Theoretical Studies ◽

Stress Strain ◽

Stress Strain State ◽

Actual Stress

Abstract In order to study the stress-strain state of the elements of joints on glued washers, a computational model of a multi-row joint on glued steel washers has been developed. The picture and character of the actual stress-strain state of a wooden element with glued washers are obtained. By analyzing the stress-strain state of the wooden element, the optimal step of the arrangement of washers in a multi-row connection is determined.

Download Full-text

RESEARCH OF INFLUENCE OF UNFINISHED CONSTRUCTION EXCAVATION ON STRESS-STRAIN STATE OF EXPLOITED BUILDING BEARING STRUCTURES

Building constructions. Theory and Practice ◽

10.32347/2522-4182.2.2018.3-12 ◽

2018 ◽

Vol 0 (2) ◽

pp. 3-12

Author(s):

A Banakh

Keyword(s):

Strain State ◽

Stress Strain ◽

Stress Strain State

Download Full-text

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

Open Information and Computer Integrated Technologies ◽

10.32620/oikit.2020.88.02 ◽

2020 ◽

pp. 15-30

Author(s):

А. Г. Гребеников ◽

И. В. Малков ◽

В. А. Урбанович ◽

Н. И. Москаленко ◽

Д. С. Колодийчик

Keyword(s):

Finite Element ◽

Strain State ◽

Layer Structure ◽

Metal Structure ◽

Element Model ◽

Stress Strain ◽

Element Analysis ◽

Mesh Structure ◽

Stress Strain State ◽

Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

Download Full-text