NUMERICAL MODELING AND FULL-SCALE EXPERIMENTS OF GLUED WOODEN STRUCTURES JOINT DESTRUCTION ON CARBON-FIBER DOWEL PINS

This paper presents the results of numerical modeling and full-scale experiments of the failure process of a glued laminated timber beam with rigid joint in the middle. All the connecting parts are made of carbon fiber. The structural analysis is done with the finite element method (ANSYS software). The nonlinear problem was solved. The contact interaction of the structural elements in the process of deformation and fracture, as well as orthotropy of the wood, the transversely isotropic properties of the plates, and the real diagrams of the deformation of carbon fiber dowel pins were taken into account. The influence of the structural parameters of the joint on the position of the most loaded dowel pin in the joint and the bearing capacity of the general structure are investigated. To verify the structural analysis results, field tests were carried out before destruction by a stepwise increasing load on a personally designed stand. The destruction of the structure occurred according to the forecast of the numerical model as a result of the mutual slip of the glued wood layers and the destruction of the polymer matrix of the glued dowel pins with the beginning of the formation of plastic joints and the formation of cracks in the wood at the junction.

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Numerical investigations of work of driven pile on claystones

Vestnik MGSU ◽

10.22227/1997-0935.2019.2.188-198 ◽

2019 ◽

pp. 188-198

Author(s):

Evgeniya N. Sychkina ◽

Vadim V. Antipov ◽

Yan V. Ofrikhter

Keyword(s):

Finite Element ◽

Numerical Modeling ◽

Software Package ◽

Field Experiments ◽

Field Tests ◽

Full Scale ◽

Elastic Model ◽

Element Analysis ◽

Pile Settlement ◽

Plaxis 3D

Introduction. Reviewed the features of the work of the pile on Permian claystones with the help of numerical and field experiments, analytical calculations. Materials and methods. Numerical modeling was performed in the Plaxis 3D and Midas GTS NX software packages. Full-scale tests of driven piles are made in accordance with the requirements of GOST 20276-2012. The obtained results are compared with the results of analytical calculations according to SP 24.13330.2011. Results. The scientific novelty of the investigation consists in a comparative analysis of the results of numerical modeling of the interaction of a driving pile with claystones with the results of field tests and analytical calculations. Finite element analysis in software package Plaxis 3D using Hardening Soil model shows higher values of settlement (up to 6 times) in relation to stabilized settlement of full-scale pile tests. Calculations in the software package Midas GTS NX showed overestimated values of pile settlements in relation to full-scale pile tests (13-24 times). Analytical calculations in accordance with SP 24.13330.2011 also showed overestimated (up to 3 times) values of the maximum pile settlement in relation to the stabilized settlement during full-scale pile tests. Conclusions. The calculations by the finite element method in the package Plaxis 3D and Midas GTS NX, by the analytical method according to SP 24.13330.2011, show overestimated values of settlement in relation to the stabilized settlement of piles on claystones. Using the Linear-Elastic model for claystones in numerical calculations in Plaxis 3D provides a value close to the settlement of full-scale pile. However, the use of this model is not fully justified for claystones due to the presence of residual deformations and the nonlinear character of pile settlement during loading. Necessary to correct the existing numerical and analytical methods for calculating pile foundations on claystones. It is necessary to continue the work on the further generalization of the experience of arranging piles on weathered claystones in order to evaluate the long-term work of not only a single pile, but also a pile foundation.

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Effect of guy cable constraint on structural damping of open lattice antenna towers

Canadian Journal of Civil Engineering ◽

10.1139/l80-074 ◽

1980 ◽

Vol 7 (4) ◽

pp. 614-620

Author(s):

J. S. Kennedy ◽

D. J. Wilson ◽

P. F. Adams ◽

M. Perlynn

Keyword(s):

Natural Frequencies ◽

Damping Ratio ◽

Field Tests ◽

Full Scale ◽

Structural Damping ◽

Scale Field ◽

Modes Of Vibration

This paper presents the results of full-scale field tests on two steel guyed latticed towers. The towers were approximately 83 m in height, were guyed at three levels, and were of bolted angle construction. The observed results consist of the natural frequencies of the first two modes of vibration as well as the damping ratio for the first mode. The observed results are compared with analytical predictions and observations made concerning the contributions of structural and cable action to the damping ratio.

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THE RULE OF COMBINING A PRIORI AND EXPERIMENTAL INFORMATION IN THE TASKS OF MANAGING TESTS OF COMPLEX TECHNICAL PRODUCTS ACCORDING TO THE BERNOULLI SCHEME

Vestnik komp iuternykh i informatsionnykh tekhnologii ◽

10.14489/vkit.2020.12.pp.003-013 ◽

2020 ◽

pp. 3-13

Author(s):

Yu. I. Buryak ◽

A. A. Skrynnikov

Keyword(s):

Field Experiments ◽

A Priori ◽

Field Tests ◽

Experimental Information ◽

Full Scale ◽

Testing Complex ◽

Series Of Experiments ◽

Full Scale Tests ◽

Technical Products

The article is devoted to the substantiation of the procedure for testing complex technical systems to assess the probability of performing the task, taking into account a priori data obtained from the results of modeling, field tests of components and prototypes, operation of analogues, etc. The conditions for the formation of a combined sample consisting of field experiments and experiments counted on the results of modeling are justified. Data uniformity is checked using the Student's criterion. The minimum volume of full-scale tests is determined by the requirement of equality of the amount of Fischer information about the estimated parameter obtained during full-scale tests and at the expense of a priori data A strategy for conducting field experiments is proposed, in which the required quality of evaluating the probability of completing the task is achieved with the minimum possible number of field experiments. At the first stage, a series of experiments with a volume equal to half of the required sample size is performed. At the second stage, the experiments are conducted sequentially with an assessment after each experiment of the requirements for the amount of information about the evaluated parameter and for the uniformity of data. Experiments are terminated when the specified requirements are met, and then a combined sample is formed, which is used to evaluate the probability of the system performing the task. A model example is considered. The estimation of the gain in the number of experiments performed at different probability values was carried out.

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Study of the effect of the reinforcement direction on the identification of relaxation transitions of moisture-saturated carbon fiber VKU-25

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2021-87-9-38-43 ◽

2021 ◽

Vol 87 (9) ◽

pp. 38-43

Author(s):

O. G. Ospennikova ◽

P. S. Marakhovsky ◽

N. N. Vorobyov ◽

E. V. Nikolaev ◽

A. I. Gulyaev ◽

...

Keyword(s):

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Carbon Fiber ◽

Polymer Matrix ◽

Structural Parameters ◽

Polymer Materials ◽

Thermal Coefficient ◽

Initial State ◽

Relaxation Transitions

Thermodilatometric methods of analysis are used to study the structural parameters of polymer materials, however, when studying moisture-saturated compositions certain difficulties arise in their identification. The results of thermophysical tests of VKU-25 carbon fiber samples in the initial state and after moisture saturation are presented. It is shown that heat treatment of materials affects the recorded values of the glass transition temperature of the epoxy matrix. When the samples are exposed in water or above the water surface, the sorbate penetrates into the polymer at the same rate, which is confirmed by almost identical values of water absorption at the same exposure time. The estimates of the thermal coefficient of linear expansion (TCLE) of the samples in the range of 20 - 250°C are given. Moreover, it is shown that the glass transition temperature of the plasticized polymer matrix depends on the direction of fiber reinforcement. In the case of moisture-saturated carbon fiber (CF)heated to 210°C, the formation of main cracks occurs mainly at the fiber-matrix interface. The glass transition temperature (GTT) of the material in the dry state (176 - 177°C), appeared almost independent on the heating rate, whereas for water-saturated samples, GTT changes significantly and can be described by a polynomial of the 2nd order. After exposure of the carbon fiber under conditions of high temperature and humidity, two relaxation transitions corresponding to the systems occur in the polymer matrix: epoxidian oligomer— amine hardener and polyfunctional resin— amine hardener. The glass transition temperature is 132 and 159°C in the first and in the second, respectively. The results obtained can be used in the development of new polymer composite materials.

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Effective Instrumentation Plan and Analysis Methodology for Full-Scale Field Tests of Concrete Pavements

Journal of Transportation Engineering Part B Pavements ◽

10.1061/jpeodx.0000084 ◽

2019 ◽

Vol 145 (1) ◽

pp. 04018055

Author(s):

Sangyoung Han ◽

Kukjoo Kim ◽

Sanghyun Chun ◽

Mang Tia

Keyword(s):

Field Tests ◽

Full Scale ◽

Concrete Pavements ◽

Analysis Methodology ◽

Scale Field

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Rockfall Full Scale Field Tests

Landslide Science and Practice ◽

10.1007/978-3-642-31445-2_60 ◽

2013 ◽

pp. 461-467

Author(s):

Alberto Clerici ◽

Ezio Giuriani ◽

Danilo Cambiaghi ◽

Antonio Isceri ◽

Giorgio Vassena ◽

...

Keyword(s):

Field Tests ◽

Full Scale ◽

Scale Field

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Numerical Modeling of Failure Process in Cohesive Geomaterials

Springer Series in Geomechanics and Geoengineering - Bifurcation and Degradation of Geomaterials in the New Millennium ◽

10.1007/978-3-319-13506-9_7 ◽

2014 ◽

pp. 39-45

Author(s):

C. Yao ◽

Q. H. Jiang ◽

J. F. Shao

Keyword(s):

Numerical Modeling ◽

Failure Process

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Numerical modeling of acoustic emission during rock failure process using a Voronoi element based – explicit numerical manifold method

Tunnelling and Underground Space Technology ◽

10.1016/j.tust.2018.05.009 ◽

2018 ◽

Vol 79 ◽

pp. 175-189 ◽

Cited By ~ 5

Author(s):

Quansheng Liu ◽

Yalong Jiang ◽

Zhijun Wu ◽

Zhicheng Qian ◽

Xiangyu Xu

Keyword(s):

Numerical Modeling ◽

Acoustic Emission ◽

Failure Process ◽

Rock Failure ◽

Numerical Manifold Method ◽

Rock Failure Process ◽

Numerical Manifold

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CREATING A WORKING MODEL OF A DRIVERLESS AIRFIELD TOW TRUCK

Bulletin of Bryansk state technical university ◽

10.30987/1999-8775-2021-10-45-52 ◽

2021 ◽

Vol 2021 (10) ◽

pp. 45-52

Author(s):

Denis D'yakov ◽

Iskander Valiulin ◽

Dmitriy Lihovidov ◽

Aleksey Velikanov

Keyword(s):

Research Methods ◽

Economic Efficiency ◽

Experimental Studies ◽

Field Tests ◽

Climatic Conditions ◽

Full Scale ◽

Support Surface ◽

Reliable Operation ◽

Working Model ◽

Full Scale Tests

The purpose of the research in this paper is to develop a promising airfield driverless tow truck to increase the economic efficiency of aircraft towing facilities, including unmanned aircrafts as well as to ensure reliable operation in various climatic conditions. The research methods include the analysis of the experience of using such driverless airfield tow trucks abroad, the theory of calculating traction and speed indicators and experimental studies conducted during the creation and study of field tests of devices used to load the driving wheels of a tractor. To achieve the goal, the configuration of the structure being designed and its intended composition are determined analytically. The operation of the designed device in the traction mode is considered, and the characteristic of calculating its indicators when moving along the support surface is presented. The presented material briefly illustrates the process from creating a model of a driverless airfield tow truck to the created design of an existing sample, which will later be used to conduct its full-scale tests and a comprehensive assessment of its strength traction and speed characteristics.

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