Mechanical Response of Structural Elements to Dynamic Loads

1989 ◽  
Author(s):  
George Herrmann
Keyword(s):  
Mechanical Response ◽  
Dynamic Loads ◽  
Structural Elements

scholarly journals Determination of stress concentration near the holes under dynamic loadings

2021 ◽  
pp. 19-24
Author(s):  
O Maksymovych ◽  
T Solyar ◽  
A Sudakov ◽  
I Nazar ◽  
M Polishchuk
Keyword(s):  
Stress Concentration ◽  
Laplace Transform ◽  
Integral Equations ◽  
Dynamic Loads ◽  
Initial Time ◽  
Structural Elements ◽  
Dynamic Problems ◽  
Dynamic Stresses ◽  
Method Of Integral Equations ◽  
The Laplace Transform

Purpose. To develop an approach for determining the stress state of plate structural elements with holes under dynamic loads with controlled accuracy. Methodology. The study was carried out on the basis of the Laplace transform and the method of integral equations. Findings. An approach to determining the dynamic stresses at the holes in the plates is proposed, which includes: the Laplace transform in the time coordinate; a numerical method for determining transformants of displacements and stresses based on the method of integral equations; finding originals on the basis of Prudnikovs formula adapted to dynamic problems of elasticity theory. The problem of determining the Laplace images for displacements is reduced to solving singular integral equations. Integral equations were solved numerically based on the approaches developed in the boundary element method. To find displacements and stresses, the Laplace transform inversion formulas proposed by Prudnikov are adapted to dynamic problems. The study on dynamic stresses at holes of various shapes was carried out. Originality. A new approach to the regularization of the Prudnikov formula for inverting the Laplace transform as applied to dynamic problems of the theory of elasticity has been developed. For its implementation: convergence of Fourier series based on pre-set stresses at the initial time is improved; the remainder is taken into account in the conversion formula. Practical value. A method has been developed for calculating the stress concentration at holes of arbitrary shape in lamellar structural elements under dynamic loads. The proposed approach makes it possible to determine stresses with controlled accuracy. The studies performed at circular and polygonal holes with rounded tops can be used in strength calculations for dynamically loaded plates. The influence of Poissons ratio on the concentration of dynamic stresses is analyzed.

Numerical methods in construction

2018 ◽  
Author(s):  
Владимир Чемодуров ◽  
Vladimir Chemodurov ◽  
Элла Литвинова ◽  
Ella Litvinova
Keyword(s):  
Numerical Methods ◽  
Differential Equations ◽  
Strain State ◽  
System Analysis ◽  
Dynamic Loads ◽  
Analytical Models ◽  
Building Structures ◽  
Structural Elements ◽  
Complex Technical Systems ◽  
Technical Systems

The monograph deals with the development of models of stress-strain state of structural elements, the study of the behavior of building structures under the influence of dynamic loads using differential equations; methods of discretization of analytical models of the functioning of building structures and design of complex technical systems (system analysis problems). It is intended for scientific and technical workers, it will be useful to students in the areas of training 08.03.01 and 08.04.01 "Construction".

Mechanical Response and FEM Modeling of Porous Al under Static and Dynamic Loads

2013 ◽  
Vol 16 (3) ◽  
pp. 289-294 ◽  
Author(s):  
N. Michailidis ◽  
E. Smyrnaios ◽  
G. Maliaris ◽  
F. Stergioudi ◽  
A. Tsouknidas
Keyword(s):  
Mechanical Response ◽  
Dynamic Loads ◽  
Fem Modeling ◽  
Static And Dynamic Loads

scholarly journals Analysis of Pavement Structures. By Animesh Das. CRC Press: Boca Raton, FL, USA, 2014; 194p; ISBN 978-1466558557

2021 ◽  
Vol 13 (11) ◽  
pp. 6098
Author(s):  
Ali Jamshidi
Keyword(s):  
Soil Layer ◽  
Dynamic Loads ◽  
Internal Stresses ◽  
Building Structures ◽  
Structural Elements ◽  
Moving Loads ◽  
Full Contact ◽  
Pavement Structures ◽  
Materials Used ◽  
Structure Height

Significant differences exist between pavement and building structures, particularly with respect to the type and mode of loading conditions: structural elements, beams and columns of buildings are subjected to static loads and pavement to dynamic loads. However, the design of structural members for buildings might need to address temporary dynamic loads due to wind, earthquake or other factors depending on building or structure height and application. In contrast, pavements are subjected to the moving loads of vehicles as well as to further loads due to temperature gradients. Since the layers of various materials used in pavements may vary in thickness and the statically indeterminate nature of pavement (due to the full contact with the bed soil layer or the lower layers), any deformation caused by changes in the moisture content and temperature can result in internal stresses in pavement structures. Consequently, analysis of pavement structures can be very complicated, requiring skills in material characterization, mathematics and modeling. In this regard, a useful book that covers various subjects in the pavement design and analysis was reviewed. Th details of each chapter were briefly explained. This book is recommended for consultant engineers and pavement researchers.

scholarly journals Mechanical Behaviour at Low Strains of LDPE Foams with Cell Sizes in the Microcellular Range: Advantages of Using These Materials in Structural Elements

2008 ◽  
Vol 27 (6) ◽  
pp. 347-362 ◽  
Author(s):  
M.A. Rodriguez-Perez ◽  
J. Lobos ◽  
C.A. Perez-Muñoz ◽  
J.A. de Saja ◽  
L. Gonzalez ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Cell Size ◽  
Mechanical Behaviour ◽  
Cellular Structure ◽  
Mechanical Response ◽  
Young's Modulus ◽  
Production Method ◽  
Constant Density ◽  
Structural Elements ◽  
Compression Moulding

This paper presents the production method and the compressive mechanical response at low strains for a collection of polyethylene foams with high densities and cell sizes in the microcellular range. The materials were produced using an improved compression moulding technique that allows and independent control of density and cell size. The materials had a relative density between 0.27 and 0.92, an homogeneous and multi-structured cellular structure with dense skin and foamed core and cell sizes in the range 30 to 100 microns. The Young's modulus decreased with density. For relative densities higher than 0.7, the reduced Young's modulus of the foams was higher than that of the solid. In addition, it has been proved that variations in the cell size at constant density did not influence the Young's modulus. The advantages of using these materials for the production of plastic pipes have been analysed. In comparison with a solid pipe a reduction of the weight of foamed pipes loaded in compression of up to 40% can be reached.

scholarly journals Development and study of mechanical behaviour reinforcing composites by waste BTP

2018 ◽  
Vol 149 ◽  
pp. 02012
Author(s):  
M.El kanzaoui ◽  
A. Hajjaji ◽  
A. Guenbour ◽  
R. Boussen
Keyword(s):  
Composite Materials ◽  
Mechanical Response ◽  
Industrial Applications ◽  
Waste Materials ◽  
Structural Elements ◽  
Ceramic Filler ◽  
Metal Structures ◽  
Stiffness Properties ◽  
Strength And Stiffness ◽  
Very High

Composite materials are used in many industrial applications for their excellent mechanical and electric properties and their low density compared to metal structures. Most countries are extremely rich waste materials such as white ceramic breakages which represents a potential to be developed. Ceramic breakages have exceptional properties and could be effectively exploited in the manufacture of composite materials for a wide variety of applications. The composite materials reinforced by construction waste materials, such as ceramic breaks which offer significant benefits and gains in strength and stiffness properties (Young's modulus E : a material whose modulus Young is very high is said rigid).This article covers the benefits of breakages as ceramic filler used for reinforcement in composites, as well as improve the mechanical response of these structural elements (test compression).

Material-Specific Joining Techniques for Magnesium Body Structures

2005 ◽  
Vol 488-489 ◽  
pp. 357-360 ◽  
Author(s):  
Ortwin Hahn ◽  
S. Schumann ◽  
G. Meschut ◽  
T. Fuhrmann
Keyword(s):  
Die Casting ◽  
The Body ◽  
Dynamic Loads ◽  
Structural Elements ◽  
Vehicle Structure ◽  
Body In White ◽  
Static And Dynamic Loads ◽  
Thin Walled ◽  
Maximum Utilization ◽  
Made In

In order to achieve further reductions in the weight of the body-in-white, efforts are being made in the field of car design to replace structural elements by magnesium components. In addition to the use of extrusion and sheet metal processes, die casting in particular is an especially important method of producing thin-walled, highly integrative components, because of the very good casting properties of magnesium. Integrating of die casted components into a vehicle structure calls for joining techniques which offer the maximum utilization of the materials of the joined parts under operating loads. This article discusses the necessity for material-specific joining techniques for future magnesium body structures. Using the example of aluminium/magnesium joints, the article describes the benefits of different joining techniques with regard to their efficient use of material in the case of both quasi-static and dynamic loads.

scholarly journals Loads of road vehicles during piggyback transportation

2019 ◽  
Vol 298 ◽  
pp. 00109 ◽  
Author(s):  
Aleksandr Tsyganov
Keyword(s):  
Technical Condition ◽  
Dynamic Loads ◽  
Rolling Stock ◽  
Rail Transportation ◽  
Structural Elements ◽  
Road Vehicles ◽  
Dynamic Forces ◽  
The Impact ◽  
Railway Rolling Stock

The impact of rail transportation on road vehicles that are placed in flatcars is considered in the article. The features of piggyback transportation and the dynamic forces acting on road vehicles in railway rolling stock are determined. The change dependences of the values of dynamic forces for different masses of road vehicles in the longitudinal and transverse directions are established. It is concluded that road vehicles that are used in regular piggyback transportation will experience significant dynamic loads of structural elements, which requires monitoring of their technical condition. Consequently, the infrastructure of piggyback terminals that load and unload road vehicles onto railway rolling stock should include the availability of automobile service facilities.

scholarly journals A Study of the Occurrence of Resonance under the Influence of Dynamic Forces on the Structural Elements of Electrical Installations

2021 ◽  
Vol 64 (3) ◽  
pp. 228-238
Author(s):  
Ya. V. Potachits
Keyword(s):  
Short Circuit ◽  
Dynamic Loads ◽  
Forced Oscillations ◽  
Structural Elements ◽  
Destructive Effect ◽  
Reliable Determination ◽  
Dynamic Task ◽  
Electrical Devices ◽  
Dynamic Forces ◽  
The Republic

The increase in the levels of short-circuit currents in the power system of the Republic of Belarus requires the study of the parameters of the electrodynamic stability of the main structural elements of electrical installations with flexible conductors. In case of a short circuit in the network, currents tenfold exceeding the rated one hundreds of times can flow through the current-carrying part of the device. When the magnetic fields formed by these currents interact, significant electromagnetic forces arise, which have a destructive effect both on the current-carrying parts themselves and on the structural elements of electrical installations, viz. support insulators, switching devices, measuring equipment. The movement of the wires in a short-circuit mode leads to the appearance of significant dynamic loads in them, which, in turn, are transmitted to the portals, support insulators and electrical devices. A topical problem is the occurrence of unacceptable mechanical forces in the main structural elements that can cause their destruction. Thus, the analysis of the physical and mechanical parameters and geometric dimensions of the flexible busbar of switchgear shows that a violation of the condition of electrodynamic resistance to tension is unlikely due to the high mechanical strength of the large-section steel-aluminum wires used. At the same time, span-limiting portals, support insulators and other electrical devices have significantly lower permissible bending loads. When exposed to dynamic forces, the conductors bend and transfer the load to the structural elements which have certain elasticity. Thus, a reliable determination of dynamic loads, taking into account the current-carrying parts acting on the supporting structures, is possible only if a dynamic task is set. The article describes the methods of mathematical modeling and computational experiment for analyzing the parameters of the electro-dynamic stability of the main structural elements which are determined using coefficients that depend on the natural frequencies of oscillations and the nature of changes in dynamic forces over time. To solve these problems, mathematical models are compiled and boundary value problems are formulated for calculating the electrodynamic stability of structural elements, taking into account the possible coincidence of the frequencies of natural and forced oscillations of structural elements taking into account the probable coincidence of the frequencies of forced and natural vibrations of structural elements.

Sign in / Sign up

Export Citation Format

Share Document