scholarly journals A Multilevel Product Model for Simulation-Based Design of Mechanical Systems

1998 ◽  
Vol 6 (2) ◽  
pp. 131-144 ◽  
Author(s):  
Kuang-Hua Chang ◽  
Kyung K. Choi ◽  
Jeff Wang ◽  
Chung-Shin Tsai ◽  
Edwin Hardee
Author(s):  
Kuang-Hua Chang ◽  
Kyung K. Choi ◽  
Jeff J. Y. Wang ◽  
Chung-Shin Tsai ◽  
Edwin Hardee

Abstract This paper presents a two-level product modeling method that supports Simulation-Based Design (SBD) of mechanical systems, primarily ground vehicles and heavy equipment, for preliminary and detailed design. A Computer-Aided Design (CAD) model combined with engineering parameters and mathematical equations that describe physical behavior of the mechanical system constitute its product model for SBD. For preliminary design, improvement of system performance, including dynamics and human factors, is the primary focus. A CAD model with reasonably accurate physical parameters, such as mass properties, is defined as the base definition of the product model. A parametric study can be conducted to search for design alternatives using dimension parameters created in the parameterized CAD model. Component designs are the primary focus in the detailed design stage. A detailed product model is evolved from that of the preliminary design, by refining geometric representation of mechanical components in CAD and expanding product assembly into parts and sub-assemblies for further engineering analysis. In the detailed design stage, a systematic design trade-off method is usually needed for design improvement. In both design stages, CAD and Computer-Aided Engineering (CAE) mappings that tie dimension parameters in the CAD model and physical parameters of simulation models facilitate the parametric study and design trade-off by quickly generating simulation models to simulate performance of the modified design. A High Mobility Multi-Purpose Wheeled Vehicle (HMMWV) is employed to illustrate and demonstrate the modeling method.


Author(s):  
Edwin Hardee ◽  
Chung-Shin Tsai ◽  
Kyung K. Choi

Abstract An intranet-based tool for integrating an enterprise-wide simulation-based design and manufacturing environment for mechanical systems is presented. The tool is invoked as a Java applet from a web page. Users can browse global product model data from the applet and retrieve and store product data between the global product data server (called the Design Data Server) and their local workspaces. Network connections are based on the CORBA standard. This environment enables the achievement of concurrent engineering goals. It gives the members of an enterprise-wide product development team a convenient, uniform interface to the global product data from different platforms. It allows their various simulation and modeling tools on the different platforms to interoperate through the Design Data Server.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1877
Author(s):  
Widha Kusumaningdyah ◽  
Tetsuo Tezuka ◽  
Benjamin C. McLellan

Energy transitions are complex and involve interrelated changes in the socio-technical dimensions of society. One major barrier to renewable energy transitions is lock-in from the incumbent socio-technical regime. This study evaluates Energy Product–Service Systems (EPSS) as a renewable energy market mechanism. EPSS offer electricity service performance instead of energy products and appliances for household consumers. Through consumers buying the service, the provider company is enabled to choose, manage and control electrical appliances for best-matched service delivery. Given the heterogenous market players and future uncertainties, this study aims to identify the necessary conditions to achieve a sustainable renewable energy market. Simulation-Based Design for EPSS framework is implemented to assess various hypothetical market conditions’ impact on market efficiency in the short term and long term. The results reveal the specific market characteristics that have a higher chance of causing unexpected results. Ultimately, this paper demonstrates the advantage of implementing Simulation-Based Design for EPSS to design retail electricity markets for renewable energy under competing market mechanisms with heterogenous economic agents.


Author(s):  
Takeshi D. Itoh ◽  
Takaaki Horinouchi ◽  
Hiroki Uchida ◽  
Koichi Takahashi ◽  
Haruka Ozaki

In automated laboratories consisting of multiple different types of instruments, scheduling algorithms are useful for determining the optimal allocations of instruments to minimize the time required to complete experimental procedures. However, previous studies on scheduling algorithms for laboratory automation have not emphasized the time constraints by mutual boundaries (TCMBs) among operations, which is important in procedures involving live cells or unstable biomolecules. Here, we define the “scheduling for laboratory automation in biology” (S-LAB) problem as a scheduling problem for automated laboratories in which operations with TCMBs are performed by multiple different instruments. We formulate an S-LAB problem as a mixed-integer programming (MIP) problem and propose a scheduling method using the branch-and-bound algorithm. Simulations show that our method can find the optimal schedules of S-LAB problems that minimize overall execution time while satisfying the TCMBs. Furthermore, we propose the use of our scheduling method for the simulation-based design of job definitions and laboratory configurations.


Author(s):  
Samir Kumar Hati ◽  
Nimai Pada Mandal ◽  
Dipankar Sanyal

Losses in control valves drag down the average overall efficiency of electrohydraulic systems to only about 22% from nearly 75% for standard pump-motor sets. For achieving higher energy efficiency in slower systems, direct pump control replacing fast-response valve control is being put in place through variable-speed motors. Despite the promise of a quicker response, displacement control of pumps has seen slower progress for exhibiting undesired oscillation with respect to the demand in some situations. Hence, a mechatronic simulation-based design is taken up here for a variable-displacement pump–controlled system directly feeding a double-acting single-rod cylinder. The most significant innovation centers on designing an axial-piston pump with an electrohydraulic compensator for bi-directional swashing. An accumulator is conceived to handle the flow difference in the two sides across the load piston. A solenoid-driven sequence valve with P control is proposed for charging the accumulator along with setting its initial gas pressure by a feedforward design. Simple proportional–integral–derivative control of the compensator valve is considered in this exploratory study. Appropriate setting of the gains and critical sizing of the compensator has been obtained through a detailed parametric study aiming low integral absolute error. A notable finding of the simulation is the achievement of the concurrent minimum integral absolute error of 3.8 mm s and the maximum energy saving of 516 kJ with respect to a fixed-displacement pump. This is predicted for the combination of the circumferential port width of 2 mm for the compensator valve and the radial clearance of 40 µm between each compensator cylinder and the paired piston.


Author(s):  
Valeriy Sukharev ◽  
Jun-Ho Choy ◽  
Armen Kteyan ◽  
Henrik Hovsepyan ◽  
Uwe Muehle ◽  
...  

Potential challenges with managing mechanical stress and the consequent effects on device performance for advanced 3D IC technologies are outlined. The growing need for a simulation-based design verification flow capable of analyzing and detecting across-die out-of-spec stress-induced variations in MOSFET/FinFET electrical characteristics is highlighted. A physics-based compact modeling methodology for multi-scale simulation of all contributing components of stress induced variability is described. A simulation flow that provides an interface between layout formats (GDS II, OASIS), and FEA-based package-scale tools, is also developed. This tool, can be used to optimize the floorplan for different circuits and packaging technologies, and/or for the final design signoff, for all stress induced phenomena. Finally, a calibration technique based on fitting to measured electrical characterization data is presented, along with correlation of the electrical characteristics to direct physical strain measurements.


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