Auswahl der wissenschaftlichen Literatur zum Thema „Statics and dynamics parameters“

SummaryThe DELTA parallel robot, designed by an EPFL (Ecole Polytechnique Fédérale de Lausanne) research team, is a mechanical structure which has the advantage of parallel robots and ease of serial robots modeling. This paper presents solutions for a complete modeling of the DELTA parallel robot (direct and inverse kinematics, inverse statics, inverse dynamics), with few arithmetic and trigonometric operations. Our method is based on a satisfactory choice of kinematic parameters and on a few restricting hypotheses for the static and dynamic models. We give some details of each model, we present some computation results and we put the emphasis on some particular points, showing the capabilities of this mechanical structure.

In this work, we propose the method for the investigation of stochastic vibrations of deterministic mechanical systems represented by axially symmetric spherical shells. These structure members are widely used as sensitive elements of pressure measuring devices in various branches of measuring and control industry, machine design, and so forth. The proposed method can be easily extended for the investigation of shallow spherical shells, goffer-type membranes, and so on. The so-called charts of control parameters for a shell subjected to a transversal uniformly distributed and local harmonic loading force and resistance moment are constructed. The scenarios of the transition of vibration of shallow-type system into chaotic state are investigated with the use of the theory of differential equations and the theory of nonlinear dynamics. The method of the control of chaotic vibrations of flexible spherical shells subjected to a transversal harmonic load through a synchronized action of either harmonic resistance moment or force is proposed, illustrated, and discussed.

This paper replaces increasing product variety with quality upgrading in the Romer model [Romer, Paul M., Journal of Political Economy 98 (1990), S71–S102]. We show that the range of parameters for which a steady state exists can be divided into two subspaces with well-behaved comparative statics and saddle-point dynamics in one subspace, but with “perverse” comparative-statics properties and either equilibrium indeterminacy or instability in the other subspace. These results for the closed economy can also be used to characterize the dynamics of the M-country open-economy version of the model.

The subject of this work is the problem of describing the dynamic behavior of the price in the market of one product. The typical balance of interaction of supply and demand functions depending on the price is considered. The dynamic model of price evolution is based on the assumption that the demand function at a given time depends on the supply function at all previous points in time, i.e. there is a process with an aftereffect. The core of the integral transformation is a characteristic of the second order, which can initiate periodic regimes in price variables. The aim of the work is to synthesize a mathematical model of price changes in the market of one product and study the stability of its equilibrium states with the manifestation of the structure of marginal cycles. The task of the study is to demonstrate the degree of connection between the problem of stability of equilibrium and the problem of obtaining fruitful results in comparative statics. This duality is the principle of conformity of P. Samuelson. The basic mathematical model of the studied process of price dynamics is a system of two nonlinear differential equations of the first order. The research methods are the nonlinear theory of analysis of dynamical systems, the mathematical theory of stability of systems of differential equations, the conceptual apparatus of analysis of typical bifurcations of birth (death) of the boundary cycle, known as the Andronov-Hopf bifurcation. As a result of a detailed analysis of the properties and parameters of self-oscillating modes, a double cycle is revealed, i.e. there is a fact of coexistence around the equilibrium state of stable and unstable limit cycles. Subsequent mathematical transformations prove that the line of demarcation of these two cycles is completely determined by the static parameters of the studied system, which illustrates the mechanism of action of the principle of conformity of P. Samuelson. Conclusions: on the example of the functioning of the labor market, a comprehensive analysis of the stability of two positive equilibrium states, which characterize the effects of substitution and income. Computer simulations are used to perform computational experiments that demonstrate self-oscillating modes of price changes. As a result of the analysis of the obtained numerical results, it is possible to draw a conclusion about the stability of the limit cycle in the vicinity of the equilibrium state, which corresponds to the substitution effect.

Selecting the optimal parameters for wet steam accumulator of steam-powered catapult is an important task, due to launching safety. There is no literature on the topic of the parameters optimization for wet steam accumulator of steam-powered catapult. The genetic algorithm (GA) was used to determine the optimal wet steam accumulator in this article. The sink-off-the-bow (SOB), angle of attack and rate of climb were used to create the objective function. The multi-objective optimization can be converted to single-objective optimization, which is subject to angle of attack and rate of climb. Moreover, the simulation model of the steam catapult system was built by creating a thermodynamics model of steam-powered catapult, a mathematical model of traction release device, a statics model of tensioning, a statics model of full takeoff power, a mathematical model of catapult force build-up with holdback, a model of release, a dynamics model of power stroke, a dynamics model of free deck run and a dynamics model of fly away. Finally, the optimal combination of the wet steam accumulator was obtained via numerical simulation. The GA method can effectively find the optimal parameters of wet steam accumulator, and its optimized parameters can increase the safety of catapult launch process.

By researching the dynamics of high speed friction and wear test system, establish the statics and dynamics model of high-speed dial and get the equation of motion of turntable scrapers state. Using Ansys Workbench software platform analysis the order modal of the turntable, get the kinetic parameters of the system. Some suggestion and methods are proposed on avoiding vibration of turntable system.

A lattice design of a cloak for full two-dimensional elasticity is suggested when the background continuum is isotropic with Lamé parameters (λ, μ ) satisfying μ ≤ λ. The lattice is polar in the sense that it elastically resists rotations; and is degenerate meaning it admits a stressless collapse mechanism. These characteristics are attained through the use of appropriately distributed restoring torques in conjunction with hinge-like spring-mass contacts. Thus, the lattice is proven to exhibit a rank-3 elasticity tensor lacking the minor symmetries. Accordingly, it rigorously adheres to the form-invariance requirements of the transformation method under the Brun–Guenneau–Movchan gauge. The cloak is numerically tested in statics and in dynamics under pressure and shear incident waves and shows satisfactory performance. Finally, a theoretical generalization extends the design to three dimensions and to arbitrarily anisotropic backgrounds so as to enable cloaking as well as other transformation-based static and dynamic field manipulation techniques in these cases.

With the increasing development of ocean engineering, towing extending-retracting equipment used widely is the basic platform realizing the engineer value of towfish. In this paper, the dynamic model of the equipment in rough sea condition is created based on Adams, and the operating parameters are determined by maximum dynamic load, as the input data of static model of the equipment. Then the static models of capture unit, swing arm and base frame are created to calculate the strength respectively. Lastly, from the results, the valuable suggestions are put forward to provide valuable references for optimization design and engineer application in future.

Proper foam statics index can give essential indications on foam dynamic behavior in porous media. In this paper, the statics characteristics are investigated through air-flow method for foam generated with Sodium Dodecyl Sulfate (SDS) surfactant. Parameters of foam height, foam half period time are recorded for various gas phases, surfactant concentrations and injecting gas flow rate, and foam morphology are also visually monitored. It is found the N2 generated foam has better characteristics on foam height, while poorer characteristics on foam half-time period compared to air and CO2 foam. Widely employed Foam Composite Index (FCI) is no longer suitable for predicting foam dynamic behavior, a Foam Index for predicting Dynamic Behavior in Porous Media (FIDBPM) is therefore defined to predict properly the foam transient propagation process in porous media.

The paper aims at identifying metaphorization of quantitative lexemes as a basic means to form quantifiers. The research objective is to develop a classification of qualitative parameters for the Italian and French quantifiers. In particular, a structural approach is used, based on such methods of material analysis as the comparative-typological method, contextual analysis, and the method of lexicographic definitions. The authors pay attention to the identification of qualitative parameters, a set of properties that characterizes the quantifiers under study. All identified parameters are analysed in a comparative manner. The authors have pointed to such parameters as deicticity, statics / dynamics, connotation, homogeneity / heterogeneity, simultaneity / sequence.