scholarly journals Robust design from systems physics

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Andrei A. Klishin ◽  
Alec Kirkley ◽  
David J. Singer ◽  
Greg van Anders

Abstract A crucial challenge in engineering modern, integrated systems is to produce robust designs. However, quantifying the robustness of a design is less straightforward than quantifying the robustness of products. For products, in particular engineering materials, intuitive, plain language terms of strong versus weak and brittle versus ductile take on precise, quantitative meaning in terms of stress–strain relationships. Here, we show that a “systems physics” framing of integrated system design produces stress–strain relationships in design space. From these stress–strain relationships, we find that both the mathematical and intuitive notions of strong versus weak and brittle versus directly characterize the robustness of designs. We use this to show that the relative robustness of designs against changes in problem objectives has a simple graphical representation. This graphical representation, and its underlying stress–strain foundation, provide new metrics that can be applied to classes of designs to assess robustness from feature- to system-level.

Author(s):  
Jin Wang ◽  
Nickolas Vlahopoulos ◽  
Zissimos P. Mourelatos ◽  
Omidreza Ebrat ◽  
Kumar Vaidyanathan

This paper presents the development of surrogate models (metamodels) for evaluating the bearing performance in an internal combustion engine. The metamodels are employed for performing probabilistic analyses for the engine bearings. The metamodels are developed based on results from a simulation solver computed at a limited number of sample points, which sample the design space. An integrated system-level engine simulation model, consisting of a flexible crankshaft dynamics model and a flexible engine block model connected by a detailed hydrodynamic lubrication model, is employed in this paper for generating information necessary to construct the metamodels. An optimal symmetric Latin hypercube algorithm is utilized for identifying the sampling points based on the number and the range of the variables that are considered to vary in the design space. The development of the metamodels is validated by comparing results from the metamodels with results from the actual simulation models over a large number of evaluation points. Once the metamodels are established they are employed for performing probabilistic analyses. The initial clearance between the crankshaft and the bearing at each main bearing and the oil viscosity comprise the random variables in the probabilistic analyses. The maximum oil pressure and the percentage of time (the time ratio) within each cycle that a bearing operates with oil film thickness less than a user defined threshold value at each main bearing constitute the performance variables of the system. The availability of the metamodels allows comparing the performance of several probabilistic methods in terms of accuracy and computational efficiency. A useful insight is gained by the probabilistic analysis on how variability in the bearing characteristics affects its performance.


Liquidity ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 32-41
Author(s):  
Amrizal Amrizal

Banking industry is very tight competition in all aspects. Results review from some literatures: journals and empirical data indicates that the banking industry has been applied information technology in order to provide excellent service to customers in the form of electronic transactions such as ATM, sms banking, e-commerce and so forth. Based on Bank Indonesia reports, the type of electronic transaction has been growing very rapidly between the transaction and Bilyetgiro Elekteronik Checks, ATM, Credit Card, Account Card Based (ATM and Debit Cards), Electronic Money, Delivery Chanel and RTGS. Those above transactions are relating to the Technology Information System and Integrated System. Integrated system is the combination of Hardskill which focus on knowledge and more to the integrity softskill (shidiq, trustworthy, tablig, fathonah). Islamic banks are ready to face competition both nationally and internationally, primarily face competition from the aspect of Integrated Systems. Bank Syariah Mandiri (BSM) developed e-banking features on an ongoing basis, among others


1981 ◽  
Vol 103 (4) ◽  
pp. 322-329 ◽  
Author(s):  
T. E. Stripling ◽  
R. G. Holter

Several long-distance, high-volume coal slurry transportation systems are planned or proposed for the United States. These new systems offer a method of transport that is both economical and environmentally attractive. The design of these systems will be a challenge to the pipeline engineer since an integrated, system design of several components is necessary to achieve an optimum overall effect. The pipeline, pump stations, instrumentation and controls, slurry preparation, and utilization facilities must all be considered in the design. The purpose of this paper is to describe the system components of a large coal slurry transportation system in detail and to show the special design considerations required for the overall system design considering the interrelationships of the various components.


2012 ◽  
Vol 52 (4) ◽  
pp. 486-493 ◽  
Author(s):  
Beata Feledyn-Szewczyk

Abstract The research was conducted from 2008 to 2010, and compared the influence of different weed control methods used in spring wheat on the structure of the weed communities and the crop yield. The study was carried out at the Experimental Station of the Institute of Soil Science and Plant Cultivation - State Research Institute in Osiny as part of a long-term trial where these crop production systems had been compared since 1994. In the conventional and integrated systems, spring wheat was grown in a pure stand, whereas in the organic system, the wheat was grown with undersown clover and grasses. In the conventional system, herbicides were applied two times in a growing season, but in the integrated system - only once. The effectiveness of weed management was lower in the organic system than in other systems, but the dry matter of weeds did not exceed 60 g/m2. In the integrated system, the average dry matter of weeds in spring wheat was 4 times lower, and in the conventional system 10 times lower than in the organic system. Weed diversity was the largest in spring wheat cultivated in the organic system. In the conventional and integrated systems, compensation of some weed species was observed (Viola arvensis, Fallopia convolvulus, Equisetum arvense). The comparison of weed communities using Sorenson’s indices revealed more of a similarity between systems in terms of number of weed species than in the number of individuals. Such results imply that qualitative changes are slower than quantitative ones. The yield of grain was the biggest in the integrated system (5.5 t/ha of average). It was 35% higher than in the organic system, and 20% higher than in conventional ones.


Author(s):  
Zsolt Lattmann ◽  
Adam Nagel ◽  
Jason Scott ◽  
Kevin Smyth ◽  
Chris vanBuskirk ◽  
...  

We describe the use of the Cyber-Physical Modeling Language (CyPhyML) to support trade studies and integration activities in system-level vehicle designs. CyPhyML captures parameterized component behavior using acausal models (i.e. hybrid bond graphs and Modelica) to enable automatic composition and synthesis of simulation models for significant vehicle subsystems. Generated simulations allow us to compare performance between different design alternatives. System behavior and evaluation are specified independently from specifications for design-space alternatives. Test bench models in CyPhyML are given in terms of generic assemblies over the entire design space, so performance can be evaluated for any selected design instance once automated design space exploration is complete. Generated Simulink models are also integrated into a mobility model for interactive 3-D simulation.


Author(s):  
Sudhakar Y. Reddy

Abstract This paper describes HIDER, a methodology that enables detailed simulation models to be used during the early stages of system design. HIDER uses a machine learning approach to form abstract models from the detailed models. The abstract models are used for multiple-objective optimization to obtain sets of non-dominated designs. The tradeoffs between design and performance attributes in the non-dominated sets are used to interactively refine the design space. A prototype design tool has been developed to assist the designer in easily forming abstract models, flexibly defining optimization problems, and interactively exploring and refining the design space. To demonstrate the practical applicability of this approach, the paper presents results from the application of HIDER to the system-level design of a wheel loader. In this demonstration, complex simulation models for cycle time evaluation and stability analysis are used together for early-stage exploration of design space.


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