scholarly journals Least-thickness symmetric circular masonry arch of maximum horizontal thrust

2021 ◽  
Author(s):  
Giuseppe Cocchetti ◽  
Egidio Rizzi
Keyword(s):  
Optimization Problem ◽  
Research Work ◽  
Complementary Information ◽  
Masonry Arch ◽  
Collapse Mode ◽  
Hinge Position ◽  
Explicit Representations ◽  
Horizontal Thrust ◽  
Structural Optimization Problem ◽  
Typical Solution

AbstractThis analytical note shall provide a contribution to the understanding of general principles in the Mechanics of (symmetric circular) masonry arches. Within a mainstream of previous research work by the authors (and competent framing in the dedicated literature), devoted to investigate the classical structural optimization problem leading to the least-thickness condition under self-weight (“Couplet-Heyman problem”), and the relevant characteristics of the purely rotational five-hinge collapse mode, new and complementary information is here analytically derived. Peculiar extremal conditions are explicitly inspected, as those leading to the maximum intrinsic non-dimensional horizontal thrust and to the foremost wide angular inner-hinge position from the crown, both occurring for specific instances of over-complete (horseshoe) arches. The whole is obtained, and confronted, for three typical solution cases, i.e., Heyman, “CCR” and Milankovitch instances, all together, by full closed-form explicit representations, and elucidated by relevant illustrations.

Robust Layout Synthesis of a MEM Crab-Leg Resonator Using a Constrained Genetic Algorithm

2007 ◽  
Author(s):  
Zhun Fan ◽  
Sofiane Achiche
Keyword(s):  
Genetic Algorithm ◽  
Robust Design ◽  
Optimization Problem ◽  
Design Method ◽  
Research Work ◽  
Constrained Optimization Problem ◽  
Geometric Uncertainties ◽  
Layout Synthesis ◽  
Target Performance ◽  
Robust Design Method

The research work carried out in this paper introduces a robust design method for layout synthesis of MEM resonator subject to inherent geometric uncertainties such as the fabrication error on the sidewall of the structure. The robust design problem is formulated as a multi-objective constrained optimization problem with certain assumptions and treated by a special constrained genetic algorithm. The MEM design used for validation is a crab-leg resonator taken from the literature. The results show that the approach proposed in this research can lead to design results that meet the target performance and are less sensitive to geometric uncertainties than typical designs.

Size and Pretension Optimization Design of Deployable Cable-Frame Antenna Structures

2015 ◽  
Vol 777 ◽  
pp. 101-105
Author(s):  
Ya Li Zong ◽  
Hong Jun Cao ◽  
Ya Jing Ma
Keyword(s):  
Structural Optimization ◽  
Optimization Model ◽  
Optimization Design ◽  
Optimization Problem ◽  
Antenna Structure ◽  
Cable Network ◽  
Surface Precision ◽  
Supporting Frame ◽  
Member Size ◽  
Structural Optimization Problem

In this paper, the structural optimization problem of a deployable cable-frame antenna consisting of a cable network and a supporting frame is discussed in detail. Firstly, the initial equilibrium problem of the cable-frame antenna structure is discussed with emphasis on the realization convenience. An optimization model is proposed to get a set of uniformly distributed cable pretensions whilst satisfying the surface precision requirement. Secondly, the optimization of the member size and cable tensions are integrated in one optimization model in which both folded and deployed status are considered. Finally, a 10-meter antenna is optimized with good results which indicates that the proposed method is feasible and effective.

Online Hybrid Model Predictive Controller Design for Cruise Control of Automobiles

2017 ◽  
Author(s):  
Kaveh Merat ◽  
Jafar Abbaszadeh Chekan ◽  
Hassan Salarieh ◽  
Aria Alasty
Keyword(s):  
Hybrid Model ◽  
Optimization Problem ◽  
Controller Design ◽  
Research Work ◽  
Mixed Integer ◽  
Control Procedure ◽  
Cruise Control ◽  
Model Predictive Controller ◽  
Gear Shift ◽  
Predictive Controller

In the proposed study, a Hybrid Model Predictive Controller is introduced for cruise control of an automobile model. The presented model consists of the engine, the gearbox, and the transmission dynamics, where the aerodynamics force and elastic friction between the tires and road are taken into account. Through Piecewise Linearization of nonlinearities in the system; (torque)-(throttle)-(angular velocity) of engine and (aerodynamic drag force)-(automobile velocity), a comprehensive piecewise linear model for the system is obtained. Then combined with the switch and shift between engaged gears in gearbox, the Piecewise Affine (PWA) model for the vehicle dynamics is acquired. As far as the control design is concerned, the cruise control problem for tracking a desired speed fashion is addressed by a MPC-based controller design. The proposed control approach is based on the online model predictive control, applied on the obtained PWA dynamics. The highlighted novelties of the presented research work are summarized as: first a more complete model is examined due to the consideration of a realistic model for engine. This improvement makes the polyhedron regions of the PWA system dependent to both state variable (i.e., velocity) and input signals (i.e., throttle and engaged gear) which brings the complexity to the design of control procedure. Second, due to the switch in the dynamics and dependence of our PWA model to discrete input (gear shift), the desperate need to solve the optimization problem through mixed integer programming, which needs high computation effort specially for our system, seems inevitable. We triumph over this challenge through introducing “possible gear shift scenario” sets. Hence, by constraining the optimization problem to the introduced logical sets, the problem still remains convex optimization type and the computation volume is reduced. In addition, we hired branch and bound method which allowed us to have large problems to be solved in a tractable amount of time and computation resources. At last, some simulations are presented to exhibit the performance of the proposed method.

A random tunneling algorithm for the structural optimization problem

2002 ◽  
Vol 4 (19) ◽  
pp. 4782-4788 ◽  
Author(s):  
Haiyan Jiang ◽  
Wensheng Cai ◽  
Xueguang Shao
Keyword(s):  
Structural Optimization ◽  
Optimization Problem ◽  
Structural Optimization Problem

scholarly journals Multi-view Clustering via Late Fusion Alignment Maximization

2019 ◽  
Author(s):  
Siwei Wang ◽  
Xinwang Liu ◽  
En Zhu ◽  
Chang Tang ◽  
Jiyuan Liu ◽  
...  
Keyword(s):  
Computational Complexity ◽  
Iterative Algorithm ◽  
Optimization Problem ◽  
Optimization Procedure ◽  
Multiple Views ◽  
Late Fusion ◽  
Complementary Information ◽  
Benchmark Datasets ◽  
Effectiveness And Efficiency ◽  
Consensus Partition

Multi-view clustering (MVC) optimally integrates complementary information from different views to improve clustering performance. Although demonstrating promising performance in many applications, we observe that most of existing methods directly combine multiple views to learn an optimal similarity for clustering. These methods would cause intensive computational complexity and over-complicated optimization. In this paper, we theoretically uncover the connection between existing k-means clustering and the alignment between base partitions and consensus partition. Based on this observation, we propose a simple but effective multi-view algorithm termed {Multi-view Clustering via Late Fusion Alignment Maximization (MVC-LFA)}. In specific, MVC-LFA proposes to maximally align the consensus partition with the weighted base partitions. Such a criterion is beneficial to significantly reduce the computational complexity and simplify the optimization procedure. Furthermore, we design a three-step iterative algorithm to solve the new resultant optimization problem with theoretically guaranteed convergence. Extensive experiments on five multi-view benchmark datasets demonstrate the effectiveness and efficiency of the proposed MVC-LFA.

Multi-Objective Evolutionary Algorithms

2016 ◽  
pp. 301-345
Author(s):  
A. K. Nandi ◽  
K. Deb
Keyword(s):  
Genetic Algorithm ◽  
Evolutionary Algorithms ◽  
Optimization Problem ◽  
Performance Metrics ◽  
Research Work ◽  
Primary Objective ◽  
Multi Objective Optimization ◽  
Nsga Ii ◽  
Mould Material ◽  
Multi Objective

The primary objective in designing appropriate particle reinforced polyurethane composite which will be used as a mould material in soft tooling process is to minimize the cycle time of soft tooling process by providing faster cooling rate during solidification of wax/plastic component. This chapter exemplifies an effective approach to design particle reinforced mould materials by solving the inherent multi-objective optimization problem associated with soft tooling process using evolutionary algorithms. In this chapter, first a brief introduction of multi-objective optimization problem with the key issues is presented. Then, after a short overview on the working procedure of genetic algorithm, a well- established multi-objective evolutionary algorithm, namely NSGA-II along with various performance metrics are described. The inherent multi-objective problem in soft tooling process is demonstrated and subsequently solved using an elitist non-dominated sorting genetic algorithm, NSGA-II. Multi-objective optimization results obtained using NSGA-II are analyzed statistically and validated with real industrial application. Finally the fundamental results of this approach are summarized and various perspectives to the industries along with scopes for future research work are pointed out.

On the Prediction of Extremal Material Properties and Optimal Material Distribution for Multiple Loading Conditions

1994 ◽  
Author(s):  
Martin P. Bendsøe ◽  
Alejandro R. Díaz ◽  
Robert Lipton ◽  
John E. Taylor
Keyword(s):  
Material Properties ◽  
Optimization Problem ◽  
Simultaneous Optimization ◽  
Elastic Continuum ◽  
Linear Elastic ◽  
Recent Developments ◽  
Multiple Loading ◽  
Optimal Material ◽  
The Cost ◽  
Structural Optimization Problem

Abstract This paper describes some recent developments that treats the simultaneous optimization of material and structure for minimum compliance. The basic idea is to represent the material properties for a linear elastic continuum in the most general form possible namely as the unrestricted set of elements of positive semi-definite constitutive tensors. The cost of resource is measured through certain invariants of the tensors, here the 2-norm or the trace of the tensors. The advantage of this general formulation is that analytical forms for the optimized material properties can be derived and that effective methods for computational solution can be devised for the resulting reduced structural optimization problem.

Modeling of a Controlled Service Platform: Proposals for an Optimal Layout

1996 ◽  
Author(s):  
H. Eschenauer ◽  
P. Neuser
Keyword(s):  
Optimization Problem ◽  
Optimization Procedure ◽  
Optimal Layout ◽  
Fe Method ◽  
Service Platform ◽  
System Reduction ◽  
Extreme Load ◽  
Structural Responses ◽  
Improved Design ◽  
Structural Optimization Problem

Abstract As an example of complex systems a controlled service platform is treated, for which an improved design has to be determined. Two substitute models that simplify the real system to a different degree are employed for the calculation of the structural responses by means of the Finite-Element (FE)-Method. The structural analyses are limited to the consideration of the system’s free vibration behaviour, as well as the displacements and stresses in an extreme load case, called bumper impact. A further system reduction is achieved by using sub-structuring and the reduction according to Guyan. The structural optimization problem is solved by means of the optimization procedure SAPOP that is based on the so-called Three-Columns-Concept. Results are given for a design optimized with respect to mass, first eigenfrequency, and stress.

Solution of the Structural Optimization Problem of a Multiagent Approach Based Cutter Design

2019 ◽  
Vol 22 (1) ◽  
pp. 53-59
Author(s):  
Valerii Anosov ◽  
◽  
Lina Bohdanova ◽  
Volodymyr Kolodiazhnyi ◽  
Vadym Litovka ◽  
...  
Keyword(s):  
Structural Optimization ◽  
Optimization Problem ◽  
Cutter Design ◽  
Structural Optimization Problem
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