Optimal design of structures based on energy theorems in case of time-dependent loading with dissipation

2000 ◽  
Author(s):  
Anna Vasarhelyi ◽  
Janos Logo
Keyword(s):  
Optimal Design ◽  
Time Dependent

A Supply Network’s Optimal Information System and Material Flows

2013 ◽  
Vol 6 (3) ◽  
pp. 86-104 ◽  
Author(s):  
Frenck Waage
Keyword(s):  
Information System ◽  
Optimal Design ◽  
Time Dependent ◽  
Optimal Management ◽  
Supply Network ◽  
Material Flows ◽  
Facility Locations ◽  
Demand Pull ◽  
Optimal Network ◽  
Optimal Information

The management of a supply network is repeatedly forced to react to changes that have occurred, and to pro-act to changes that may occur. Management would certainly find it useful to have available a model which could identify the optimal re-action, or pro-action, from among all those which are possible. This paper will: (1) describe how such a model can be constructed in practice, and (2) how the model can be solved for the optimal management pro-actions, and reactions. The model describes all supply network interactions at any moment in time, and it describes all time dependent supply network interactions dynamically. The model serves as management’s optimal real-time decision support/information system. It will dynamically calculate the optimal operations policy for the entire supply network. The model is also capable of identifying: the optimal design of a supply network, the optimal capacities of a network, and the optimal network facility locations. It also solves some well known problems such as what is the optimal pure “demand – pull” policy in a network?

Optimal design of a commercial rubber isolator based on creep and creep-resistance analyses

2021 ◽  
pp. 095440622110171
Author(s):  
Dingxin Leng ◽  
Yi Yang ◽  
Demin Li ◽  
Yong Ma ◽  
Guijie Liu ◽  
...  
Keyword(s):  
Finite Element ◽  
Optimal Design ◽  
Constitutive Model ◽  
Creep Resistance ◽  
Time Dependent ◽  
Nonlinear Creep ◽  
Rubber Material ◽  
Creep Analysis ◽  
Creep Constitutive Model ◽  
Rubber Isolator

Creep is a common important physical phenomenon in rubber material, which induces the instability of geometrical dimension and deteriorates the mechanical performances. The present work develops an optimal design approach of a commercial rubber isolator based on creep analysis. First and foremost, a nonlinear creep constitutive model of rubber material is established, which can capture the hyper-elastic and time-dependent creep behaviors. Complete mechanical and creep tests of rubber materials are conducted, and material parameters are identified according to the experimental data. Then, the parametric finite element model of a rubber isolator is established, with which the time-dependent creep analysis based on the proposed creep constitutive model is conducted. The accuracy of the numerical creep analysis is validated at material level and structural component level. For engineering application, a sensitivity analysis and optimization design for creep-resistance of the rubber isolator is developed by combing finite element simulation and optimization method. The results show that creep-resistance characteristics of the optimal rubber isolator is largely improved, which provides a long-term stable behavior in vibration attenuation. The proposed method may provide an efficient tool for predicting the creep performance and optimal analysis of other commercial rubber-base products.

Optimal Design of a Series-Parallel System with Time-Dependent Reliability

1977 ◽  
Vol R-26 (2) ◽  
pp. 119-120 ◽  
Author(s):  
Kyoichi Nakashima ◽  
Kazuharu Yamato
Keyword(s):  
Optimal Design ◽  
Parallel System ◽  
Time Dependent

Optimal Heater Control in Thermoforming Preheating Using Approximate Function

2011 ◽  
Vol 314-316 ◽  
pp. 576-580
Author(s):  
Zhen Zhe Li ◽  
Gui Ying Shen ◽  
Mei Qin Li ◽  
Xiao Qian Wang ◽  
Yun De Shen
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Optimal Design ◽  
Temperature Difference ◽  
Time Dependent ◽  
Function Form ◽  
Analysis Model ◽  
Order Polynomial ◽  
Approximate Function

Thermoforming is one of the most versatile and economical processes available for shaping polymer products. To improve the quality of final products, the temperature difference between surface and center of sheet should be continuously minimized. But, the temperature difference between surface and center of sheet can not be freely reduced because of low thermal conductivity of sheet materials. In this paper, an analysis model was developed under the condition that the inputted heat flux was expressed by an exponential function form. In the following step, an optimal design was carried out using a 3rd order polynomial. The optimal results show that the developed method can be used to reduce the temperature difference between surface and center of sheet by adjusting the parameter of time-dependent heat flux.

Time-dependent reliability and optimal design of scraper chains based on fretting wear process

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shuai Li ◽  
Zhencai Zhu ◽  
Hao Lu ◽  
Gang Shen
Keyword(s):  
Optimal Design ◽  
Physical Model ◽  
Fretting Wear ◽  
Time Dependent ◽  
Dynamic Tension ◽  
Content Type ◽  
Dynamic Reliability ◽  
Wear Process ◽  
Scraper Conveyor ◽  
Wear Modes

Purpose This paper aims to present a dynamic reliability model of scraper chains based on the fretting wear process and propose a reasonable structural optimization method. Design/methodology/approach First, the dynamic tension of the scraper chain is modeled by considering the polygon effect of the scraper conveyor. Then, the numerical wear model of the scraper chain is established based on the tangential and radial fretting wear modes. The scraper chain wear process is introduced based on the diameter wear rate. Furthermore, the time-dependent reliability of scraper chains based on the fretting wear process is addressed by the third-moment saddlepoint approximation (TMSA) method. Finally, the scraper chain is optimized based on the reliability optimization design theory. Findings There is a correlation between the wear and the dynamic tension of the scraper conveyor. The unit sliding distance of fretting wear is affected by the dynamic tension of the scraper conveyor. The reliability estimation of the scraper chain with incomplete probability information is achieved by using the TMSA for the method needs only the first three statistical moments of the state variable. From the perspective of the chain drive system, the reliability-based optimal design of the scraper chain can effectively extend its service life and reduce its linear density. Originality/value The innovation of the work is that the physical model of the scraper chain wear is established based on the dynamic analysis of the scraper conveyor. And based on the physical model of wear, the time-dependent reliability and optimal design of scraper chains are carried out.

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