Modelling and simulation of complex mechanical systems with applications to a steam-generating system Part 2. Numerical simulation

Abstract Two types of problems are dealt with in the paper which are involved in the design of mechanisms required to have specified dynamic characteristics: (1) Determination of applied forces required to produce specified dynamic characteristics. (2) Determination of the dynamic characteristics which will result from the application of known forces. While graphical methods may be used in the solution of type (1) problems involving more or less complex mechanical systems, they do not afford a direct approach to type (2) problems. The energy method which will be outlined can be applied in either case, although this paper will be primarily concerned with the determination of the dynamic characteristics which result when a known force is applied to a given mechanism.

Download Full-text

A Form Verification System for the Conceptual Design of Complex Mechanical Systems

19th Design Automation Conference: Volume 1 — Mechanical System Dynamics; Concurrent and Robust Design; Design for Assembly and Manufacture; Genetic Algorithms in Design and Structural Optimization ◽

10.1115/detc1993-0297 ◽

1993 ◽

Author(s):

Jonathan S. Colton ◽

Mark P. Ouellette

Keyword(s):

Conceptual Design ◽

Process Model ◽

Mechanical Systems ◽

Data Representation ◽

Design System ◽

Complex Data ◽

Graphical Display ◽

Design Environment ◽

Blackboard System ◽

Complex Mechanical Systems

Abstract This paper presents a summary of research into the development and implementation of a domain independent, computer-based model for the conceptual design of complex mechanical systems (Ouellette, 1992). The creation of such a design model includes the integration of four major concepts: (1) The use of a graphical display for visualizing the conceptual design attributes; (2) The proper representation of the complex data and diverse knowledge required to design the system; (3) The integration of quality design methods into the conceptual design; and (4) The modeling of the conceptual design process as a mapping between functions and forms. Using the design of an automobile as a case study, a design environment was created which consisted of a distributed problem solving paradigm and a parametric graphical display. The requirements of the design problem with respect to data representation and design processing were evaluated and a process model was specified. The resulting vehicle design system consists of a tight integration between a blackboard system and a parametric design system. The completed system allows a designer to view graphical representations of the candidate conceptual designs that the blackboard system generates.

Download Full-text

Degrading systems availability analysis: analytical semi-Markov approach

Eksploatacja i Niezawodnosc - Maintenance and Reliability ◽

10.17531/ein.2021.1.20 ◽

2021 ◽

Vol 23 (1) ◽

pp. 195-208

Author(s):

Varun Kumar ◽

Girish Kumar ◽

Rajesh Kumar Singh ◽

Umang Soni

Keyword(s):

Steady State ◽

Degradation Mechanism ◽

Continuous Process ◽

Mechanical Systems ◽

Embedded Markov Chain ◽

Steady State Probability ◽

Opportunistic Maintenance ◽

System Availability ◽

Availability Analysis ◽

Complex Mechanical Systems

This paper deals with modeling and analysis of complex mechanical systems that deteriorate with age. As systems age, the questions on their availability and reliability start to surface. The system is believed to suffer from internal stochastic degradation mechanism that is described as a gradual and continuous process of performance deterioration. Therefore, it becomes difficult for maintenance engineer to model such system. Semi-Markov approach is proposed to analyze the degradation of complex mechanical systems. It involves constructing states corresponding to the system functionality status and constructing kernel matrix between the states. The construction of the transition matrix takes the failure rate and repair rate into account. Once the steady-state probability of the embedded Markov chain is computed, one can compute the steady-state solution and finally, the system availability. System models based on perfect repair without opportunistic and with opportunistic maintenance have been developed and the benefits of opportunistic maintenance are quantified in terms of increased system availability. The proposed methodology is demonstrated for a two-stage reciprocating air compressor with intercooler in between, system in series configuration.

Download Full-text

Some Aspects Concerning The Impact Of The End Of Stroke On Hydraulic Cylinders

International conference KNOWLEDGE-BASED ORGANIZATION ◽

10.1515/kbo-2015-0139 ◽

2015 ◽

Vol 21 (3) ◽

pp. 821-824

Author(s):

Niculai Hauk

Keyword(s):

Numerical Simulation ◽

Mechanical Systems ◽

Hydraulic Cylinder ◽

Important Variable ◽

Mechanical Impact ◽

Hydraulic Cylinders ◽

The Masses ◽

The Impact ◽

Simulation Systems ◽

Classical Calculation

Abstract The increase of speeds for mechanical systems operated with hydraulic cylinder raises risks of mechanical impact of the end of the race. We are considering a number of measures to limit the impact intensity. Its size is estimated according to the masses in motion, to work pressures and to the geometry of the mechanism. Elasticity of the components is also an important variable. This paper presents a method which combines the classical calculation with numerical simulation systems.

Download Full-text