Reliability-based optimization of engineering structures

2008 ◽  
pp. 31-56
Author(s):  
John Sørensen
Keyword(s):  
Engineering Structures ◽  
Reliability Based Optimization

Reliability Based Design Optimization for Selective Excitation of the Vibration Modes of a Cantilever Spring

2012 ◽  
Vol 498 ◽  
pp. 102-114
Author(s):  
Khalil El-Hami ◽  
Abdelkhalak El Hami
Keyword(s):  
Cantilever Beam ◽  
Optimization Problems ◽  
Optimization Methods ◽  
Design Parameters ◽  
Optimization Strategy ◽  
High Dimensions ◽  
Engineering Structures ◽  
Reliability Based Design ◽  
Piezoelectric Polymer ◽  
Reliability Based Optimization

This paper is devoted to procedures for the reliability-based optimization methods of engineering structures combining measurement and sensitivity technique, for the purpose of the better sensitivity in force-gradient detection. In the experiment part of this study, the mica muscovite cantilever beam clamped-free is used. The excitation of a cantilever beam with several small sheets of piezoelectric polymer adequately glued to it selects one high-frequency vibration mode of the cantilever. The proposed strategy is design into a framework that allows the solution of optimization problems involving a several number of design parameters that characterizes the systems, including dimensional tolerance, material properties, boundary conditions, loads, and model predictions, considered to be uncertainties or variables. The proposed methodology directly supports quality engineering aspects enabling to specify the manufacturing tolerances normally required to achieve desired product reliability. Within this context, the robust design obtained is optimal over the range of variable conditions because it considers uncertainties during the optimization process. The large number of exact evaluations of problem, combined with the typically high dimensions of FE models of industrial structures, makes reliability-based optimization procedures very costly, sometimes unfeasible. Those difficulties motivate the study reported in this paper, in which a strategy is proposed consisting in the use of reliability-based optimization strategy combined with measurement and sensitivity technique specially adapted to the structures of industrial interested.

scholarly journals Reliability-based Support Optimization of Rockbolt Reinforcement around Tunnels in Rock Masses

2017 ◽  
Author(s):  
Hongbo Zhao ◽  
Zhongliang Ru ◽  
Changxing Zhu
Keyword(s):  
Rock Mass ◽  
Reliability Index ◽  
Optimization Method ◽  
Optimization Techniques ◽  
Support Vector ◽  
Reliability Optimization ◽  
Engineering Structures ◽  
Geological Conditions ◽  
Reliability Method ◽  
Reliability Based Optimization

Traditionally, the design of tunnels is based on determinate parameter values. In practice, both the performance and safety of tunnels are affected by numerous uncertainties: for example,it is difficult for engineers to predict uncertainties in geological conditions and rock mass properties. The purpose of reliability-based optimization (RBO) is to find a balanced design that is not only economical but also reliable in the presence of uncertainty. In the past few decades, numerous reliability optimization techniques have been proposed for taking uncertainty into account in the design of engineering structures. In the present study, the first-order reliability method (FORM) was used to compute the reliability index using Excel Solver. The least squares support vector machine (LSSVM) approach was adopted to build a relationship between reliability index and design variables,and the artificial bee colony (ABC) algorithm was employed for the reliability-based optimization. A proposed LSSVM/ABC-based reliability optimization method was applied to the case of a tunnel with rockbolt reinforcement. The mechanical parameters of the rock mass, in-situ stress and internal pressure were considered as the random variables. The reliability index of tunnel was analysed. The length, distance out of plane and the number of rockbolts were determined and optimized considering the uncertainty based on RBO. The proposed method improved the efficiency of RBO while maintaining high accuracy. The results showed that the proposed method not only meets the design accuracy, but also improves the efficiency of reliability-based optimization.

Lighting of Engineering Structures and Industrial Facilities New Aspects of the Topic

2018 ◽  
pp. 29-36
Author(s):  
Nikolai I. Shepetkov ◽  
George N. Cherkasov ◽  
Vladimir A. Novikov
Keyword(s):  
Fundamental Problem ◽  
Lighting Design ◽  
Aesthetic Value ◽  
Engineering Structures ◽  
Industrial Facilities ◽  
Artificial Lighting ◽  
Industrial Structures ◽  
Design Solutions ◽  
Architectural Lighting ◽  
The Aesthetic

This paper considers the fundamental problem of artificial lighting in various types and scales of industrial facilities, focusing on exterior lighting design solutions. There is a lack of interest from investors, customers and society in high­quality lighting design for industrial facilities in Russia, which in many cities are very imaginative structures, practically unused in the evening. Architectural lighting of various types of installations is illustrated with photographs. The purpose of the article is to draw attention to the aesthetic value of industrial structures, provided not only by the architectural, but also by a welldesigned lighting solution.

IMPROVEMENT OF THE HYDRAULIC EXCAVATOR BUCKET DESIGN

2019 ◽  
Vol 16 (3) ◽  
pp. 202-213 ◽  
Author(s):  
G. G. Buriy ◽  
V. S. Shherbakov ◽  
S. B. Skobelev ◽  
V. F. Kovalevskiy
Keyword(s):  
Cost Reduction ◽  
Production Costs ◽  
Hydraulic Excavator ◽  
Engineering Structures ◽  
Excavator Bucket ◽  
Productivity Increase ◽  
Hydraulic Excavators ◽  
Reducing Costs ◽  
Rational Operation ◽  
Resistance Forces

Introduction.Construction of engineering structures is impossible without building and road machines. The large volume of financing is allocated for such machines’ purchase. The main ways of reducing costs of the equipment consist in more rational operation of the equipment and also in decrease of equipment’s cost by constructive changes. The paper demonstrates the new design of the single-bucket hydraulic excavator with smaller cost.Materials and methods.The main ways of cost reduction for construction machines are more rational operation and depreciation of a design with the required characteristics’ maintaining. The paper describes constructive changes of the working equipment of the single-bucket hydraulic excavator, which allow decreasing the production costs.Results.The authors describe the new bucket design of the single-bucket hydraulic excavator. Moreover, the authors carry out the analysis of the existing buckets’ design. The paper also illustrates the functioning on bucket forces while digging process. The authors describe the solutions of the problem for productivity increase of the single-bucket in hydraulic excavators. In addition, the authors make the scheme of the bucket loading while digging process. Such scheme helps to reduce resistance forces of digging.Discussion and conclusions.As a result, the paper presents the design of the working equipment of the hydraulic excavator’s single-bucket, which allows reducing resistance forces of digging. Such results would help to establish buckets of bigger capacity and would lead to the productivity increase.

Ultrasonic Torsion Welding of Aging Resistant Al/CFRP Joints - Concepts, Mechanical and Microstructural Properties

2017 ◽  
Vol 742 ◽  
pp. 395-400 ◽  
Author(s):  
Florian Staab ◽  
Frank Balle ◽  
Johannes Born
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Materials Science ◽  
Dissimilar Materials ◽  
Material Design ◽  
Ultrasonic Welding ◽  
Fatigue Properties ◽  
Aviation Industry ◽  
Efficient Design ◽  
Engineering Structures

Multi-material-design offers high potential for weight saving and optimization of engineering structures but inherits challenges as well, especially robust joining methods and long-term properties of hybrid structures. The application of joining techniques like ultrasonic welding allows a very efficient design of multi-material-components to enable further use of material specific advantages and are superior concerning mechanical properties.The Institute of Materials Science and Engineering of the University of Kaiserslautern (WKK) has a long-time experience on ultrasonic welding of dissimilar materials, for example different kinds of CFRP, light metals, steels or even glasses and ceramics. The mechanical properties are mostly optimized by using ideal process parameters, determined through statistical test planning methods.This gained knowledge is now to be transferred to application in aviation industry in cooperation with CTC GmbH and Airbus Operations GmbH. Therefore aircraft-related materials are joined by ultrasonic welding. The applied process parameters are recorded and analyzed in detail to be interlinked with the resulting mechanical properties of the hybrid joints. Aircraft derived multi-material demonstrators will be designed, manufactured and characterized with respect to their monotonic and fatigue properties as well as their resistance to aging.

Sign in / Sign up

Export Citation Format

Share Document