LGA Connectors: An Automated Design Technique for a Shrinking Design Space

2000 ◽  
Vol 122 (3) ◽  
pp. 247-254 ◽  
Author(s):  
A. Deshpande ◽  
G. Subbarayan
Keyword(s):  
Finite Element ◽  
Nonlinear Optimization ◽  
Optimization Problem ◽  
Design Procedure ◽  
Automated Design ◽  
Optimization Techniques ◽  
Circuit Board ◽  
Element Analysis ◽  
Initial Design ◽  
Design Requirements

The ever-increasing demand for higher-density interconnection between a multi-chip module and the printed circuit board has resulted in the emergence of Land-Grid Array (LGA) connectors as an alternative to the traditional pin and socket area-array connectors. The design of high-density land-grid array connectors involves trade-off between conflicting performance requirements on the normal force, wipe, bulk resistance, contact resistance, stress, contact z-dimensional thickness, and z-compression. These stringent design requirements have significantly shrunk the space of viable designs and have necessitated automated search procedures for finding designs that satisfy the design requirements. In this paper, such an automated design procedure based on nonlinear optimization techniques is presented. The design procedure includes a general shape representation scheme based on B-spline curves and a set of programs for carrying out automated nonlinear elastic-plastic-contact finite element analysis (for a given shape) using a commercial finite element code. This automated analysis procedure is coupled with a nonlinear optimization code to carryout optimal design of LGA connectors. The design of LGA connectors is mathematically formulated as an optimization problem and nine different design cases (with representative dimensions and material) are solved to determine the influence of initial design and optimization problem formulation. It is shown that better solutions (with less stress) result if both the width and the thickness of the contacts are allowed to vary. In general, the choice of initial design strongly influences the optimal solution. A triply-curved symmetric contact shape is shown to produce the least stress of three possible common LGA shape designs. [S1043-7398(00)00403-5]

Application of Computational Mechanics to Tire Design—Yesterday, Today, and Tomorrow

2011 ◽  
Vol 39 (4) ◽  
pp. 223-244 ◽  
Author(s):  
Y. Nakajima
Keyword(s):  
Finite Element ◽  
New Technologies ◽  
Computational Mechanics ◽  
Design Procedure ◽  
Side Wall ◽  
Rolling Resistance ◽  
Optimization Techniques ◽  
Stress Strain ◽  
Element Analysis ◽  
Crown Shape

Abstract The tire technology related with the computational mechanics is reviewed from the standpoint of yesterday, today, and tomorrow. Yesterday: A finite element method was developed in the 1950s as a tool of computational mechanics. In the tire manufacturers, finite element analysis (FEA) was started applying to a tire analysis in the beginning of 1970s and this was much earlier than the vehicle industry, electric industry, and others. The main reason was that construction and configurations of a tire were so complicated that analytical approach could not solve many problems related with tire mechanics. Since commercial software was not so popular in 1970s, in-house axisymmetric codes were developed for three kinds of application such as stress/strain, heat conduction, and modal analysis. Since FEA could make the stress/strain visible in a tire, the application area was mainly tire durability. Today: combining FEA with optimization techniques, the tire design procedure is drastically changed in side wall shape, tire crown shape, pitch variation, tire pattern, etc. So the computational mechanics becomes an indispensable tool for tire industry. Furthermore, an insight to improve tire performance is obtained from the optimized solution and the new technologies were created from the insight. Then, FEA is applied to various areas such as hydroplaning and snow traction based on the formulation of fluid–tire interaction. Since the computational mechanics enables us to see what we could not see, new tire patterns were developed by seeing the streamline in tire contact area and shear stress in snow in traction.Tomorrow: The computational mechanics will be applied in multidisciplinary areas and nano-scale areas to create new technologies. The environmental subjects will be more important such as rolling resistance, noise and wear.

Design and Analysis of Viscoelastic Seismic Dampers

2002 ◽  
Author(s):  
N. Shimizu ◽  
H. Nasuno ◽  
T. Yazaki ◽  
K. Sunakoda
Keyword(s):  
Finite Element ◽  
Constitutive Relation ◽  
Time Domain ◽  
Dynamic Properties ◽  
Design Procedure ◽  
Fe Analysis ◽  
Damping Capacity ◽  
Element Formulation ◽  
Element Analysis ◽  
Equivalent Viscous Damping

This paper describes a methodology of design and analysis of viscoelastic seismic dampers by means of the time domain finite element analysis. The viscoelastic constitutive relation of material incorporating with the fractional calculus has been derived and the finite element formulation based on the constitutive relation has been developed to analyze the dynamic property of seismic damper. A time domain computer program was developed by using the formulation. Dynamic properties of hysteresis loop, damping capacity, equivalent viscous damping coefficient, and equivalent spring constant are calculated and compared with the experimental results. Remarkable correlation between the FE analysis and the experiment is gained, and consequently the design procedure with the help of the FE analysis has been established.

Dynamic – Thermal Analyses of a Structurally Reconfigured Electronics Package Onboard Mini Satellite

2014 ◽  
Vol 592-594 ◽  
pp. 2117-2121 ◽  
Author(s):  
P. Veeramuthuvel ◽  
S. Jayaraman ◽  
Shankar Krishnapillai ◽  
M. Annadurai ◽  
A.K. Sharma
Keyword(s):  
Finite Element ◽  
Printed Circuit Board ◽  
Thermal Environment ◽  
Thermal Analyses ◽  
Simulation Models ◽  
Element Model ◽  
Circuit Board ◽  
Element Analysis ◽  
Transfer Path ◽  
Vibration Responses

The electronics package in a spacecraft is subjected to a variety of dynamic loads during launch phase and suitable thermal environment for the mission life. The dynamic and thermal analyses performed for a structurally reconfigured electronics package. Two different simulation models are developed to carry out the analyses. This paper discusses in two parts, in part-1, the vibration responses are determined at various critical locations, including on the Printed Circuit Board (PCB) for the vibration loads specified by launch vehicle using Finite Element Analysis (FEA). The mechanical properties of PCB are determined from the test specimens, which are then incorporated in the finite element model. In part-2, the steady-state temperature distributions on the components and on the PCB are determined, to check the effectiveness of heat transfer path from the components to the base of the package and to verify the predicted values are within the acceptable temperature limits specified. The predicted temperature values are then compared with on-orbit observations.

Standardized Foundations Database for Combat Systems

2014 ◽  
Author(s):  
M. Harbison ◽  
W. Koon ◽  
V. Smith ◽  
P. Haymon ◽  
D. Niole ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cost Savings ◽  
Ship Design ◽  
Separate Analysis ◽  
Element Analysis ◽  
Weapon Systems ◽  
System Requirements ◽  
Design Requirements ◽  
The Cost

As a result of enhanced performance and mission requirements for Navy ships, ship design has dramatically increased the use of higher strength, lightweight steels and various local reinforcements, e.g., deck inserts, ring stiffeners, etc., in foundation designs to satisfy the design requirements for supporting machinery, consoles, and weapon systems among others. In additional to operational loading requirements, most of these foundations must also be designed to satisfy shock, vibration and other combat system requirements. While the same piece of equipment may be used in other ship contracts, the foundations are uniquely designed and require a separate analysis and drawing package. Computer modeling and Finite Element Analysis (FEA) have helped reduce the labor required to analyze foundations, but the high number of “unique” foundations as well as changes which necessitate a new analysis still create a large workload for engineers. This is further compounded by increased costs in production due to greater numbers of unique parts and materials that must be marked, stored, and retrieved later for fabrication. This goal of this project was to determine the cost-savings potential of leveraging past foundations work in designing, analyzing, and drawing foundations in the future. By the project’s conclusion Ingalls will have created a database for rapid access to previously-generated foundation information, the framework of which will be publicly available for all shipyards to populate with their own foundation information.

Finite Element Analysis of the Chassis for Sugarcane Leaf Cutting Off Returning to Field Machinery

2014 ◽  
Vol 915-916 ◽  
pp. 305-308
Author(s):  
Jing Wang ◽  
Yu Xing Wang ◽  
Yan Qin Tang ◽  
Dian Wu Zhang ◽  
Zhen Hua Xu ◽  
...  
Keyword(s):  
Finite Element ◽  
Working Conditions ◽  
Maximum Stress ◽  
Excitation Frequency ◽  
Allowable Stress ◽  
Ansys Software ◽  
Element Analysis ◽  
Stress Contour ◽  
Leaf Cutting ◽  
Design Requirements

By modeling of sugarcane leaf cutting off returning to field machinery chassis and loading, this paper simplifies reasonably several different conditions of the chassis to the two forms. The finite element is used for the solution of the problem by using ANSYS software, solving the node stress contour of the chassis. Compared the maximum stress in the most dangerous working conditions to the allowable stress of the material, the result verifies the chassis strength to meet the design requirements. According to the vibration of the chassis at work, analyzing the first sixth modal of the chassis, and comparing with excitation frequency shows that the design of the chassis avoids the excitation frequency, which does not cause resonance at work. The results show that the chassis meets the design requirements.

Structural Stability Evaluation for Lifting Lug Design of Large Marine Engine by Finite Element Analysis

2007 ◽  
Vol 353-358 ◽  
pp. 2855-2859
Author(s):  
W.C. Lee ◽  
Chae Sil Kim ◽  
J.B. Na ◽  
D.H. Lee ◽  
S.Y. Cho ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Design Procedure ◽  
Steel Structures ◽  
Stability Evaluation ◽  
Element Analysis ◽  
Marine Engines ◽  
Dimensional Finite Element ◽  
The Stability ◽  
Three Dimensional Finite Element

Since most marine engines are generally very huge and heavy, it is required to keep safety from accidents in dealing them. Several types of lifting lugs have been used to assemble hundred ton–large steel structures and carry the assembled engines. Recently a few crashes have been occurred in carrying engines due to breaking down the lugs. Although the stability evaluation of the lifting lug has therefore been very important for safety, systematic design procedure of the lugs, which includes the structural analysis considering stability, has few reported. This paper describes the three dimensional finite element structural modeling for a lifting lug, the studies for determining the reasonable loading and boundary conditions, and the stability evaluation with the results of structural analyses. It should be very helpful for designing the other types of lifting lugs with safety.

Estimation of Spring-Back of Single Torus Inner Vessel Sector by Finite Element Analysis

2016 ◽  
Vol 852 ◽  
pp. 588-594
Author(s):  
Gagan Gupta ◽  
V. Balasubramaniyan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Technology Development ◽  
Cold Pool ◽  
Spring Back ◽  
Element Analysis ◽  
Finite Element Software ◽  
Reactor Assembly ◽  
Design Requirements ◽  
Inner Vessel

Inner vessel in reactor assembly of sodium cooled fast reactor separates hot and cold pool sodium. The shape of inner vessel is optimized with reduced upper & lower shell diameters and toroidal redan for future Fast Breeder Reactor (FBR). This results in higher buckling strength and reduced thickness and hence reduced weight. To achieve the intricate toroidal shape with specified dimensional tolerances, a comprehensive technology development exercise was carried out successfully for the manufacture of inner vessel 30° sector. The achieved profile of the redan meets the specified dimensions and other design requirements. Spring-back observed in the sector was small. To verify the developmental exercise results, a finite element analysis (FEA) of forming of inner vessel sector was performed on finite element software ABAQUS. In this paper, FEA results and spring back are discussed. Spring back assessed is maximum at the center and relatively lower towards the edges for the redan with the chosen radius of 5980 mm.

scholarly journals New Design Procedure of Transtibial ProsthesisBed Stump Using Topological Optimization Method

Symmetry ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1837 ◽  
Author(s):  
Martin Sotola ◽  
David Stareczek ◽  
David Rybansky ◽  
Jiri Prokop ◽  
Pavel Marsalek
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Design Procedure ◽  
Optimization Method ◽  
Topological Optimization ◽  
Element Analysis ◽  
Current Application ◽  
Transtibial Prosthesis ◽  
Walking Biomechanics ◽  
The Impact

This paper presents a new design procedure for production of a transtibial prosthesis bed stump by three-dimensional (3D) printing with topological optimization. The suggested procedure combines the medical perspective with finite element analysis and facilitates regaining the symmetry in patients with transtibial prosthesis, which leads to life improvement. The particular focus of the study is the weight reduction of the lower part of the bed stump, while taking into account its stiffness and load-bearing capacity. The first part of the work deals with the analysis of the subject geometry of the bed stump, which is usually oversized in terms of the weight and stiffness that are necessary for the current application. In the second part, an analysis of walking biomechanics with a focus on the impact and rebound phases is presented. Based on the obtained information, a spatial model of the lower part of the bed stump is proposed in the third phase, in which the finite element method is described. In the fourth part, the topological optimization method is used for reducing the structure weight. In the last part, the results of the designed model are analyzed. Finally, the recommendations for the settings of the method are presented. The work is based on the practical industry requirements, and the obtained results will be reflected in the design of new types of transtibial prosthesis.

Finite Element Analysis of 6-Wing Synchronous Rotor in the Mixing Process

2012 ◽  
Vol 271-272 ◽  
pp. 1291-1295
Author(s):  
Cai Jun Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Analysis ◽  
Mixing Process ◽  
Element Analysis ◽  
Strain Stress ◽  
Design Requirements ◽  
Element Method

By use of finite element method to analyze the strength of 6-wing synchronous rotor, and illustrate the change of parameters regarding strain, stress and displacement etc. so as to visually see whether the designed rotor will reach the design requirements; meanwhile, through structural analysis, to provide guidance for the further optimization of designing for 6-wing synchronous rotor.

ANSYS Finite Element Analysis of a Large Space Steel Tower Frame Optimization Design Research

2012 ◽  
Vol 538-541 ◽  
pp. 520-524
Author(s):  
Fu Long Zhao
Keyword(s):  
Finite Element ◽  
Optimization Design ◽  
Design Research ◽  
System Structure ◽  
Element Calculation ◽  
Large Space ◽  
Element Analysis ◽  
Transformer Substation ◽  
Design Requirements ◽  
Steel Weight

Based on the ANSYS finite element calculation and analysis results to do the optimization design research of a large space transformer substation steel tower．To meet the constraints in steel tower frame under the minimum steel weight as the goal, the original web members of tower system structure would be optimized which was in different web members system as contrast．The optimization of the determined web members system met the design requirements and were more reasonable in economy．

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