Calculation and Experimental Technique for Determining the Damping Properties of Composite Materials

2018 ◽  
Vol 938 ◽  
pp. 46-53 ◽  
Author(s):  
Sergey I. Koryagin ◽  
O.V. Sharkov ◽  
Nikolay L. Velikanov
Keyword(s):  
Experimental Technique ◽  
Polymer Coatings ◽  
Engineering Systems ◽  
Damping Properties ◽  
Metal Structures ◽  
Experimental Specimen ◽  
Adhesive Compositions ◽  
Improved Accuracy ◽  
Damping Capability

Polymer coatings are widely used for effective vibration damping of sheet or hull structures of different engineering systems. The article presents a calculation and experimental technique that enables improved accuracy and validity of damping properties determination of polymer coatings. Mathematical models to determine the parameters of the experimental specimen having a homogenous strain state of the polymer coating are obtained. Experimentally confirmed that the use of coatings based on adhesive compositions such as "Sprut" increases by 18...28 times the damping capability in metal structures. An addition of fillers in adhesive compositions "Sprut" type in a proportion of 30...50% of its weight reduces by 2.4 times the damping properties of metal structures.

scholarly journals Determination of the region of the limiting states occurrence in RVS-20000 with the subsidence of the external bottom contour

2018 ◽  
Vol 239 ◽  
pp. 06002
Author(s):  
P.V. Chepur ◽  
A.A. Tarasenko ◽  
A.A. Gruchenkova
Keyword(s):  
Technical Condition ◽  
Element Analysis ◽  
Metal Structures ◽  
Software Complex ◽  
Managerial Decisions ◽  
The Finite Element Analysis ◽  
Steel Tank ◽  
Intrinsic Stiffness ◽  
Bottom Contour

The problem of the limiting states occurrence in the structures of a vertical steel tank is investigated in this work. To study the SSS of the metal structures of the object, the authors created a numerical model of the RVS-20000 tank in the ANSYS software complex. The model considers the maximum number of elements with their geometry and connections affecting the tank SSS under non-axisymmetric loading, including beyond the elasticity of steel. Dependences between the parameters of intrinsic stiffness of the VST are obtained. The results of the finite element analysis made it possible to develop a technique for assessing the technical condition of the structure with the development of irregular subsidence of the external bottom contour. The proposed technique can be used by both operating and design organizations in making managerial decisions regarding the repair of RVS-20000 subjected to the base subsidence.

scholarly journals EVALUATION OF THE VITALITY OF A FLANGED CONNECTION WITH A STEEL TOWER STRUCTURE WITH ACCOUNT OF EXPERIMENTAL DETERMINATION OF AERODYNAMIC COEFFICIENTS

2020 ◽  
Vol 82 (2) ◽  
pp. 215-224
Author(s):  
V.I. Erofeev ◽  
I.A. Samokhvalov
Keyword(s):  
Bearing Capacity ◽  
Numerical Study ◽  
Wind Load ◽  
Aerodynamic Coefficients ◽  
Metal Structures ◽  
Equivalent Stresses ◽  
Tower Structure ◽  
Calculation Results ◽  
Design Calculations

A numerical study of the survivability of the flange assembly is carried out upon reaching a critical load and in the presence of a defect in one of the design areas, taking into account the calculated values of the aerodynamic coefficients. An experiment is being carried out to determine the values of the wind load acting on the supporting legs of a metal tower. The calculation of the stressstrain state is performed using software system as SCAD Office and IDEA StatiCa 10.0. After calculating the forces in the core model of the structure, a threedimensional plate model of the assembly is formed and prepared for calculation. According to the results of the experiment, a graph was compiled with the values of aerodynamic coefficients, which were used in calculating the stressstrain state of the node. The analysis of the calculation results revealed that in the design (defectfree) state of the structure, the safety factor of the bearing units and elements is 35-40% (equivalent stresses were 165 MPa). If there is a defect in the metal structures of the belt in the region of the flange, the equivalent stresses increase to 247.6 MPa in the region of the cleavage (defective hole), thus, the margin in bearing capacity drops to 0.4%. As a result of the assessment of the survivability of the flange connection, it was revealed that the connection has a high potential survivability, in turn, the flange itself is able to work in the presence of some defects without reducing its bearing capacity to a critical level. The aerodynamic coefficients obtained in this work will determine the wind load on this type of profile and can be used in design calculations of tower structures for wind loads.

Robust Concurrent Concept Selection and System Synthesis

1994 ◽  
Author(s):  
Wei Chen ◽  
Janet K. Allen ◽  
Farrokh Mistree
Keyword(s):  
Irrigation System ◽  
Preliminary Design ◽  
Continuous Variables ◽  
Engineering Systems ◽  
Concept Selection ◽  
Complex Engineering ◽  
Solar Powered ◽  
System Variables ◽  
Complex Engineering Systems

Abstract In this paper, we introduce a concurrent approach to preliminary system design by using a modification of Taguchi’s method of robust design. It is possible to model interactions among component concept selections and synthesis of system variables. This approach also can improve computational efficiency and provide more design knowledge for the conceptual design of complex engineering systems. This technique is effective in dealing with both discrete and continuous variables simultaneously in design. We illustrate our approach by the preliminary design of a solar powered irrigation system. The selections of critical component concepts are integrated with the determination of system variables, i.e., the thermodynamic operating parameters.

scholarly journals A wavefront orientation method for precise numerical determination of tsunami travel time

2013 ◽  
Vol 13 (11) ◽  
pp. 2863-2870 ◽  
Author(s):  
I. V. Fine ◽  
R. E. Thomson
Keyword(s):  
Travel Time ◽  
Grid Point ◽  
Point Pattern ◽  
Numerical Determination ◽  
Computationally Efficient ◽  
Tsunami Travel Time ◽  
Orientation Method ◽  
Huygens Principle ◽  
Improved Accuracy

Abstract. We present a highly accurate and computationally efficient method (herein, the "wavefront orientation method") for determining the travel time of oceanic tsunamis. Based on Huygens' Principle, the method uses an eight-point grid-point pattern and the most recent information on the orientation of the advancing wavefront to determine the time for a tsunami to travel to a specific oceanic location. The method is shown to provide improved accuracy and reduced anisotropy compared with the conventional multiple grid-point method presently in widespread use.

scholarly journals Correction to: Determination of the Dependence of Thermal Diffusivity with Moringa Concentration by Thermal Lens as a Sensitive Experimental Technique

2020 ◽  
Vol 41 (8) ◽  
Author(s):  
R. Carbajal-Valdéz ◽  
J. L. Jiménez-Pérez ◽  
G. Gamboa-López ◽  
Z. N. Correa-Pacheco ◽  
C. Hernández-Aguilar ◽  
...  
Keyword(s):  
Thermal Diffusivity ◽  
Experimental Technique ◽  
Thermal Lens

Bestimmung der Haftzugfestigkeit dichter Beschichtungen / Determination of bond strength of impermeable polymer coatings

1999 ◽  
Vol 5 (4) ◽  
pp. 387-398
Author(s):  
R.M. Frey ◽  
F.H. Wittmann
Keyword(s):  
Bond Strength ◽  
Polymer Coatings ◽  
Theoretical Background ◽  
Gas Pressure ◽  
Blister Formation ◽  
Controlled Conditions ◽  
Porous Substrates

Abstract In many cases there is a risk for the formation of blisters if impermeable polymer coatings are applied on porous substrates. On covers of courses in sport stadiums formation of blisters has been observed recently. In this contribution a method is described which can be used to investigate the causes of blister formation in a given system. Blisters are artificially created by the application of a gas pressure in the interface between coating and substrate. In this way the growth of blisters can be varied under controlled conditions. The theoretical background of this method is outlined. In this way it is possible to estimate the necessary pressure under the cover to create blisters of the observed size.

The theory of ionisation measurements in gases at high pressures

1934 ◽  
Vol 30 (1) ◽  
pp. 80-101 ◽  
Author(s):  
D. E. Lea
Keyword(s):  
High Pressure ◽  
Experimental Determination ◽  
Experimental Technique ◽  
Alpha Particle ◽  
Reasonable Agreement ◽  
High Pressures ◽  
Industrial Research ◽  
Heavy Nuclei ◽  
Nuclear Tracks

The columnar theory developed by Jaffé to account for the recombination of ions in alpha particle tracks is extended to beta rays by taking account of the clusters of secondary ionisation. Reasonable agreement is obtained with experiment. Recombination in proton tracks produced in hydrogen by neutrons is shown to be in agreement with the columnar theory, but in the case of nitrogen nuclear tracks in nitrogen the recombination is only a hundredth of that predicted by the theory. An explanation of this effect is advanced, and it is suggested that recombination is likely to be abnormally small for all heavy nuclei of velocities not exceeding 5 × 108 cm. per sec.An experimental determination of the coefficient of recombination of ions in nitrogen and hydrogen at pressures of 20, 40 and 90 atmospheres is reported.My thanks are due to Dr Chadwick for interest in this work, and to Dr Gray and Dr Tarrant for advice on the experimental technique of high pressure ionisation measurements. I am indebted also to the Department of Scientific and Industrial Research for a maintenance grant.

Sign in / Sign up

Export Citation Format

Share Document