An Optimality Criterion for the Structural Optimization of Machine Elements

2005 ◽  
Vol 127 (3) ◽  
pp. 415-423 ◽  
Author(s):  
C.-P. Teng ◽  
J. Angeles
Keyword(s):  
Structural Optimization ◽  
Optimality Criterion ◽  
Mass Reduction ◽  
Speed Reduction ◽  
Optimum Dimension ◽  
Novel Approach ◽  
Cam Follower ◽  
Machine Elements ◽  
A Current

Methods of structural optimization have been studied and developed over the last three decades. An important aspect of structural optimization pertains to the condition under which the loads are applied. Most machine structures in operation are subject to loads varying as functions of time. In this paper, a novel approach is proposed to cope with loads whose magnitudes vary within given bounds and with variable directions. The underlying ideas are applied to the structural optimization of the roller-carrying disk of a novel class of cam-follower speed reduction devices termed Speed-o-Cam (SoC). Results obtained in this paper are compared with a current prototype and with an intermediate design in which the dimensions of the roller pins are optimized. Combined with the optimum dimension of the roller pins, our structural-optimization results lead to an improvement of almost twice the stiffness with a mass reduction of 40% of the original prototype.

A Lightweight Split-Torque Transmission for a 330 KW Helicopter

1982 ◽  
Vol 196 (1) ◽  
pp. 11-22 ◽  
Author(s):  
G White
Keyword(s):  
Gear Train ◽  
Main Rotor ◽  
Speed Reduction ◽  
Torque Transmission ◽  
Current Production ◽  
Gear Trains ◽  
Fixed Axis ◽  
Three Stages ◽  
A Current ◽  
Split Torque

A simple split-torque gear train is used as the main rotor transmission of a single-engine helicopter. Overall speed reduction ratio achieved is 103:1 between the engine at a nominal 36 000 rev/min and the main rotor at 350 rev/min. This ratio is generated from three stages of fixed-axis gear trains containing only eight gears. Alternative configurations are outlined and discussed. Comparison with a current production design shows the split torque arrangement offers reductions in weight, height, and drive train losses. A low total of gears and bearings offers the potential for improved reliability.

scholarly journals Three-Bar structure optimality criterion using the linear resizing rule

2021 ◽  
Author(s):  
José Alfredo Ramírez Monares ◽  
Jesús Israel Hernández Hernández
Keyword(s):  
Structural Optimization ◽  
Static Analysis ◽  
Optimization Model ◽  
Optimality Criterion ◽  
Minimum Mass ◽  
Design Variables ◽  
Inclination Angles ◽  
Optimization Rule

The static analysis of the indeterminate three-bar structure is developed using the Castigliano's first theorem, taking the lengths and inclination angles as variables. Some reductions are applied in the resulting set of equations to approximate them to the references models. From now on, the minimum mass optimization model with restrictions is established. Then, the Optimality Criterion linear resizing optimization rule algorithm for the unbounded and bounded design variables is applied in two numerical cases. The analytical and Matlab Optimization Toolbox results are also obtained and they demonstrate the Optimality Criterion linear resizing rule effectiveness in structural optimization with a minimum mass objective and size restrictions.

scholarly journals Pengaruh Variasi Radius-Dalam Rim Terhadap Pengurangan Massa dan Momen Inersia Massa Dengan Studi Kasus Benda Putar Berdiameter 10 cm

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Eka Taufiq Firmansjah
Keyword(s):  
Outer Radius ◽  
Moment Of Inertia ◽  
Mass Reduction ◽  
Inner Radius ◽  
Mass Moment ◽  
Mass Moment Of Inertia ◽  
Machine Elements ◽  
The Moment ◽  
The Masses

ABSTRAK Mesin terdiri dari sekumpulan elemen mesin yang diam dan bergerak. Elemen mesin yang bergerak dengan gerakan berputar disebut benda putar. Pada beberapa kasus seringkali diinginkan pengurangan massa dari benda putar tersebut untuk alasan ekonomis, biasanya untuk elemen mesin yag diproduksi massal. Namun pengurangan massa berakibat pada pengurangan momen inersia massa benda putar bersangkutan. Jika tuntutan perancangan tidak mempermasalahkan perubahan tersebut, maka pengurangan massa tidak menjadi masalah. Namun jika momen inersia massa tidak boleh terlalu rendah, maka harus dicari kompromi dimana pengurangan massa sebesar-besarnya namun penurunan momen inersia massa sekecil-kecilnya. Pada penelitian ini dilakukan studi kasus terhadap benda putar berjari- jari 10 cm jari-jari dalam hub 2 cm dan jari-jari luar hub 4 cm. Jumlah jari-jari ada 4 dengan lebar 1 cm dan tebal benda putar 0,5 cm. Variasi pengurangan massa dilakukan dengan memvariasikan jari-jari- dalam rim. Untuk tiap variasi, dilakukan perhitungan untuk mendapatkan jumlah massa yang dapat dikurangi dan momen inersia massa dari benda putar. Ternyata pada nilai jari-jari dalam tertentu, dapat diperoleh nilai kompromi dari permasalahan diatas. Kata kunci: benda putar, penghematan bahan, momen inersia massa.  ABSTRACT Machine consists of a set of machine elements that still and moving. Machine elements that move in a circular motion called rotary object. In some cases it is often desirable reduction in the mass of the rotating object for economic reasons, usually for a mass production of machine elements. But the mass reduction results in a reduction in moment of inertia of the mass. If the demands of the design allow this decrease of moment of inertia, mass reduction is not a problem. But if the moment of inertia of the masses should not be too low, it must find a compromise in which a mass reduction profusely but the decrease in the mass moment of inertia of the smallest. In this research conducted a case study of rotating element radius of 10 cm, radius of the hub 2 cm and outer radius hub 4 cm. The number of spoke are 4 with a width of 1 cm and uniform thickness 0.5 cm all over rotating element. Variations mass reduction is done by varying the inner radius of the rim. For each variation, calculation is performed to obtain the amount of mass that can be reduced and the mass moment of inertia of the rotating object. It turned out that in the certain value of inner radius of the rim in particular, can compromise the values obtained from the above problem. Keywords: rotating element, reducing material, mass moment of inertia.

Structural Configuration Examples of an Integrated Optimal Design Process

1994 ◽  
Vol 116 (4) ◽  
pp. 997-1004 ◽  
Author(s):  
M. Chirehdast ◽  
H.-C. Gea ◽  
N. Kikuchi ◽  
P. Y. Papalambros
Keyword(s):  
Structural Optimization ◽  
Design Process ◽  
Homogenization Method ◽  
Optimization Techniques ◽  
Phase Iii ◽  
Design Problems ◽  
Novel Approach ◽  
Three Phase ◽  
Bicycle Frame ◽  
Automated Procedures

Structural optimization procedures usually start from a given design topology and vary proportions or boundary shapes of the design to achieve optimality of an objective under various constraints. This article presents examples of the application of a novel approach for initiating formal structural optimization at an earlier stage, where the design topology is rigorously generated. A three-phase design process is used. In Phase I, an optimal initial topology is created by a homogenization method as a gray-scale image. In Phase II, the image is transformed to a realizable design using computer vision techniques. In Phase III, the design is parameterized and treated in detail by conventional size and shape optimization techniques. Fully-automated procedures for optimization of two-dimensional solid structures are outlined, and several practical design problems for this type of structures are solved using the proposed procedure, including a crane hook and a bicycle frame.

Structural Configuration Examples of an Integrated Optimal Design Process

1992 ◽  
Author(s):  
Mehran Chirehdast ◽  
Hae Chang Gea ◽  
Noboru Kikuchi ◽  
Panos Y. Papalambros
Keyword(s):  
Structural Optimization ◽  
Design Process ◽  
Homogenization Method ◽  
Optimization Techniques ◽  
Phase Iii ◽  
Design Problems ◽  
Novel Approach ◽  
Three Phase ◽  
Bicycle Frame ◽  
Automated Procedures

Abstract Structural optimization procedures usually start from a given design topology and vary proportions or boundary shapes of the design to achieve optimality of an objective under various constraints. This article presents examples of the application of a novel approach for initiating formal structural optimization at an earlier stage, where the design topology is rigorously generated. A three-phase design process is used. In Phase I, an optimal initial topology is created by a homogenization method as a gray-scale image. In Phase II, the image is transformed to a realizable design using computer vision techniques. In Phase III, the design is parameterized and treated in detail by conventional size and shape optimization techniques. Fully-automated procedures for optimization of two-dimensional solid structures are outlined, and several practical design problems for this type of structures are solved using the proposed procedure, including a crane hook and a bicycle frame.

A Novel Approach for the CAM-Follower Mechanism of High Frequency Cutting File Machine

2013 ◽  
Vol 333-335 ◽  
pp. 2085-2088
Author(s):  
Eurico Seabra ◽  
Hélder Puga ◽  
Luis Ferreira Da Silva
Keyword(s):  
External Force ◽  
High Frequency ◽  
Classical Mechanic ◽  
Virtual Model ◽  
Cam Mechanism ◽  
Novel Approach ◽  
Commercial Package ◽  
Cam Follower ◽  
Motion Characteristics ◽  
Positive Return

In this work, the re-design of the camfollower mechanism of an industrial cutting file machine is presented. The actual mechanical system includes a forceclosure cam mechanism, which requires an external force to keep the contact between the cam and the follower provided by a spring. This system is substituted by a new cam mechanism of the type of formclosure, which does not require external force. The formclosure camfollower mechanism, also called positive-return cam mechanism, guarantees that the cam surface is always in contact with the follower surface, and is characterized by having constantbreadth. Classical Mechanic Theory performs the study of the kinematic and dynamic characteristics of the cam mechanism analyzed throughout this work. Furthermore, a commercial package software was used to create a virtual model and analyze the motion characteristics of the new cam mechanism.

Automated Cam-Mechanism Synthesis and Analysis

1992 ◽  
Author(s):  
Arnold T. Eventoff
Keyword(s):  
Degrees Of Freedom ◽  
Visual Inspection ◽  
Synthesis Process ◽  
Mechanism Synthesis ◽  
Complete Control ◽  
Cam Mechanism ◽  
Cam Follower ◽  
Machine Elements ◽  
Computer Based ◽  
General Method

Abstract An automated computer-based method for deriving the shape of machine elements such as cams is described for complex mechanisms. Traditional cam synthesis concentrates on follower motion; the method described here enables complete control of the required output motion. Output motion is defined for any constant or variable camshaft velocity. The process is not limited by the degrees of freedom, follower shape, follower suspension, or complexity of the mechanism linking followers to output points. The method includes a velocity analysis to predict cam shape, pressure angle, and relative velocity of the follower with respect to the cam. This analysis allows immediate visual inspection and further dynamic and wear analyses. Cam-follower contact stress is readily calculated for an entire cycle of motion during the synthesis process. An example consisting of a five-bar linkage displaced by three cams is synthesized using the methodology. The general method described facilitates development of mechanisms previously not feasible using conventional methods. Servomotor command displacement profiles required for complex systems can also be derived using this method.

Structural optimization concept for the design of an aluminium control arm

2003 ◽  
Vol 217 (8) ◽  
pp. 647-656 ◽  
Author(s):  
Dong-Chan Lee ◽  
Jeong-Ick Lee
Keyword(s):  
Topology Optimization ◽  
Structural Optimization ◽  
Conceptual Design ◽  
High Performance ◽  
Optimization Design ◽  
Low Cost ◽  
Optimal Layout ◽  
Mass Reduction ◽  
Reinforcement Structure ◽  
Structural Rigidity

The development of a mechanical structure needs to be started from the conceptual design with low cost, high performance and quality. In this regard, the structural and topological shape of the system has a great e ect on the performance in terms of rigidity, strength and mass reduction. In this paper, optimization design methodologies in the design stages of an aluminium control arm for a suspension are presented. First, using topology optimization, the optimal layout and the reinforcement structure are obtained, and then the detail designs are carried out using shape optimization for the structural rigidity and strength. In comparison with a steel control arm, the mass reduction is 50 per cent and the structural rigidity and strength are improved up to 40 per cent.

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