scholarly journals Review: Modeling Damping in Mechanical Engineering Structures

2000 ◽  
Vol 7 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Michel Lalanne
Keyword(s):  
Mechanical Engineering ◽  
Engineering Structures ◽  
Damping Effects ◽  
Distributed Elements

This paper is concerned with the introduction of damping effects in the analysis of mechanical engineering structures. Damping can be considered as being generated by concentrated elements, by distributed elements, or by several effects existing simultaneously. Modeling damping for different engineering situations is described and some applications are presented briefly.

Seismic Hazard and Damages—Avoiding Disaster Through Simulation, Experiment, and Experience

1999 ◽  
Vol 121 (1) ◽  
pp. 30-36 ◽  
Author(s):  
H. Shibata
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Mechanical Engineering ◽  
Design Procedure ◽  
Shaking Table ◽  
Test Facility ◽  
Design Stage ◽  
Engineering Structures ◽  
Aseismic Design ◽  
Piping Systems

This paper deals with the role of proving tests and a large shaking test facility for equipment and piping systems in conjunction with the development of aseismic design in the field of mechanical engineering, especially for nuclear power plants in Japan. To avoid seismic disaster and damage of equipment and piping systems as well as liquid storages, we had to differentiate the seismic design procedure in mechanical engineering from that for building and civil engineering structures. For this process, the dynamic analysis in this field is more significant than for other fields. The author has been trying to develop aseismic design since the design stage of the first nuclear power plant in 1958 based on his experience as a specialist of mechanical vibration. In the early 1970s, shaking tables were developed for this purpose in Japan. The largest one in Japan is a 1000-ton 2-D table. After the 1995 Kobe earthquake, we have been developing a new 1200-ton 3-D shaking table. In the paper, the author discusses the necessity of such a facility and presents a new concept of a numerical shaking table.

Simulation of Delamination Processes of Multilayer Mechanical Engineering Structures

2021 ◽  
pp. 129-138
Author(s):  
Aleksandr Gondlyakh ◽  
Andrey Chemeris ◽  
Aleksandr Kolosov ◽  
Aleksandr Sokolskiy ◽  
Sergiy Antonyuk
Keyword(s):  
Mechanical Engineering ◽  
Engineering Structures

scholarly journals ALGORITHMIZATION OF SOLVING DYNAMIC EDGE PROBLEMS OF THE THEORY OF FLEXIBLE RECTANGULAR PLATES

2020 ◽  
pp. 143-157
Author(s):  
A. Yuldashev ◽  
◽  
Sh.T. Pirmatov ◽  
Keyword(s):  
Mechanical Engineering ◽  
Elastic Shell ◽  
Theory Of Elasticity ◽  
Automated System ◽  
Plate Motion ◽  
Rotary Inertia ◽  
Rectangular Plates ◽  
Flat Plates ◽  
Engineering Structures ◽  
Flexible Shells

In this paper, a computational algorithm is developed on the basis of the finite difference method for solving dynamic edge problems of the theory of flexible shells with account for shears and rotary inertia. Dynamic calculations of flexible plates is used in designing hulls of ships, aircraft, missiles, and other technical objects, which, along with sufficient strength, should have the least weight ensured by the use of lightweight plates and by reducing the margin of safety. The problem of developing an automated system for solving problems of the theory of elasticity and plasticity was first raised in the monograph by V.K. Kabulov. This work reveals the main problems of algorithmization and indicates approaches for their machine solution. In accordance with the analyzed problems, which arise during automated calculations of thinwalled elements of mechanical engineering structures, it is reasonable to use a nonlinear dynamic computational scheme for a flexible homogeneous isotropic linear elastic shell of arbitrary shape and to take into account the effect of both shears and rotary inertia when describing the motion of the shell. Such a model allows one to apply a sufficiently flexible and fast-acting scheme to calculate a wide class of dynamic processes taking place within the plates and shells of different shapes which are not over-limited in thickness and serve as significant parts of mechanical engineering elements. A number of dynamic differential equations of plate motion have been developed and tested. Obviously, there is no need to build other algorithms to calculate flat plates when developing an automated computational system.

Shape Optimization for Fatigue Problems Using Continuum Damage Mechanics

1999 ◽  
Author(s):  
Eckart Schnack ◽  
Wolfgang Weikl
Keyword(s):  
Shape Optimization ◽  
Mechanical Engineering ◽  
Damage Mechanics ◽  
High Cycle Fatigue ◽  
Coupled Analysis ◽  
Cycle Fatigue ◽  
Engineering Structures ◽  
Programming Technique ◽  
Meso Level ◽  
Micro Level

Abstract In mechanical engineering we are usually concerned with dynamically loaded constructions, i.e. machinery parts. In this paper a new idea for high-cycle fatigue behaviour working with the two-grid method is presented, using one grid on the micro-level and the other one for the meso-level. While on the meso-level the behaviour of the construction in high-cycle fatigue is nearly linear, however on the micro-level there are defects and microcracking with small plastic zones around the crack tips. Using a homogenization technique, we develop an energy release rate formulation on the micro-grid, from which the evolution equation for increasing damage arises. The new idea is now to define the damage at the meso-level depending on the damage at the micro-level, while controlling the stress redistribution by a modified locally coupled analysis. This leads to a new concept for shape optimization of mechanical engineering problems using the sequential quadratic programming technique. The theoretical and numerical results are controlled by experiments using a hydropulser machine. For high quality steel an increase of lifetime by a factor of about 3 was achieved for our shape optimized notched structures compared with the ones possessing classical circular cut-outs. Therefore we can say that this concept offers a new possibility for lifetime increasement of mechanical engineering structures.

scholarly journals Review: Modeling Damping in Mechanical Engineering Structures (Erratum)

2000 ◽  
Vol 7 (4) ◽  
pp. 263-263
Author(s):  
Michel Lalanne
Keyword(s):  
Mechanical Engineering ◽  
Engineering Structures

How a sheperd guides a sheep herd?

1984 ◽  
Vol 75 ◽  
pp. 331-337
Author(s):  
Richard Greenberg
Keyword(s):  
Point Of View ◽  
Single Ring ◽  
Damping Effects ◽  
Ring Particle

ABSTRACTThe mechanism by which a shepherd satellite exerts a confining torque on a ring is considered from the point of view of a single ring particle. It is still not clear how one might most meaningfully include damping effects and other collisional processes into this type of approach to the problem.

Mechanical Engineering Notes

1922 ◽  
Vol 127 (2) ◽  
pp. 133-133
Keyword(s):  
Mechanical Engineering

Mechanical engineering prospects

1975 ◽  
Vol 54 (4) ◽  
pp. 217
Keyword(s):  
Mechanical Engineering

Mesoscale observations and yearly effects in Cu-Zn-Al shape memory alloys: Representative model and predictable damping effects

2003 ◽  
Vol 112 ◽  
pp. 1155-1158 ◽  
Author(s):  
V. Torra ◽  
A. Isalgue ◽  
F. C. Lovey ◽  
M. Sade
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Representative Model ◽  
Damping Effects
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