bluuebunny/crossref_metadata_2025_split huggingface dataset:
Further Studies of General Shells by Hybrid Strain Based Triangular Elements
Authors: Liu Meilan L. , To Cho W. S. 
Published: February 2021

Abstract
This paper presents a further study of various lower-order flat triangular shell elements that were based on the Hellinger-Reissner hybrid strain formulation and were developed previously by the authors. The present investigation is to examine the effects of including membrane-bending coupling feature in the shell element formulation on the performance of the lower-order shell elements. Several features are considered. These are, for example, the membrane-bending coupling, tue linear distribution of the assumed strain field of the membrane strain, and the hybrid strain formulation with linear assumed membrane strains and membrane-bending coupling. A study on mesh topology is also included. This relatively detailed study leads one to the conclusion that the hybrid strain based flat triangular shell elements previously developed by the authors are attractive and promising for economical analysis of general shells. It is also found that the inclusion of features such as membrane-bending coupling is unnecessary. Numerical results presented here seem to strongly substantiate the theoretical developments that flat triangular shell elements do converge to the correct solution of deep shell theory. Finally it is observed that for deep shell problems appropriate mesh topology becomes the key to an accurate finite element solution.
On Simultaneous Triangularization of the Coefficients of Linear Systems
Authors: Lee W. C. , Ma F. 
Published: February 2021

Abstract
The coefficients of a linear nonconservative system are arbitrary matrices lacking the usual properties of symmetry and definiteness. An efficient way for the analysis of a nonconservative system is to reduce its coefficient matrices simultaneously to upper triangular forms. The purpose of this paper is to present some criteria for simultaneous triangularization and, when applicable, to expound a constructive procedure for triangularization.
A Combined Analytical and Numerical Approach for the Solution of an Edge Loaded Semi-Infinite Elastic Sheet
Authors: Sun Xin , Karr Dale G. , Han Chunhui 
Published: February 2021

Abstract
Edge loading of an semi-infinite elastic sheet is of interest to many engineering applications. In this paper the penetration problem involving a rigid indentor and an elastic semi-infinite sheet of uniform thickness is addressed using a combined analytical and numerical approach. The tenth-order approximate theory of stretching of an isotropic sheet is applied to formulate the governing differential equations. Solutions are then obtained using Fourier transforms for various loading conditions and numerical schemes are employed to calculate the three dimensional state of stress throughout the sheet. The influence of the aspect ratio on the resulting stress state is studied. Limit solutions for thin sheet and thick sheet are presented. Finite element analyses of the same loading conditions are also performed. Results are compared with those of the tenth-order theory and the stress distribution assumptions of the tenth-order theory are examined.
Modal Sensitivity Analysis of Coupled Acoustic-Structural Systems
Authors: Luo Jian Hui , Gea Hae Chang 
Published: February 2021

Abstract
Modal analysis of coupled acoustic-structural systems leads to unsymmetric eigenproblem of special form which introduce different left and right eigenvectors. In this paper, the relation between left and right eigenvectors is first established by symmetrization of the unsymmetric eigensystem, and then Nelson’s method is extended to coupled acoustic-structural systems for calculating the sensitivities of the eigenvalues and eigenvectors. The method only needs to calculate the sensitivities of the right eigenvectors and can treat Helmholtz resonance mode naturally. The procedure is verified to be accurate and effective by applying to an acoustic-box model.
Free External Tube Inversion Simulation Using FEM
Authors: Çolakoğlu Ali , Yıldırım R. O. , Kaftanoğlu B. 
Published: February 2021

Abstract
In this work the finite element method is employed to investigate the free external tube inversion. At the same time, quasi-static tests on cold drawn seamless mild steel tubes (BS 3602-CFS 360) with 50.8 mm (2 in) outside diameter, 1.6 mm (0.064 in) wall thickness and 203.2 mm (8 in) length are performed. The energy absorption capacities and steady-state inversion loads are observed. The finite element predictions are compared with a typical experimental result.
Midsurface Abstraction From 3D Solid Models for Engineering Analysis
Authors: Rezayat Mohsen 
Published: February 2021

Abstract
An integral part of implementing parallel product and process designs is simulation through numerical analysis. This simulation-driven design requires discretization of the 3D part in an appropriate manner. If the part is thin or has thin sections (e.g., plastic parts), then an analysis model with reduced dimensionality may be more accurate and economical than a standard 3D model. In addition, substantial simplification of some details in the design geometry may be beneficial and desirable in the analysis model. Unfortunately, the majority of CAD systems do not provide the means for abstraction of appropriate analysis models. In this paper we present a new approach, based on midsurface abstraction, which holds significant promise in simplifying simulation-driven design. The method is user-friendly because very little interaction is required to guide the software in its automatic creation of the desired analysis model. It is also robust because it handles typical parts with complex and interacting features. Application of the method for feature recognition and abstraction is also briefly discussed.
Knowledge-Based Integrated Manufacturing Flexible Simulation System
Authors: Dong Ming , Cha Jianzhong , E Mingcheng 
Published: February 2021

Abstract
In this paper, we present a knowledge-based flexible simulation system for integrated manufacturing. The simulation model knowledge base of a CIMS is constituted of five parts: FBS models of the CIM-OSA system architecture, entity classes library, procedural knowledge base, database and inference engines. The knowledge-based simulation models are represented by the object-oriented frame language and their behaviours are generated by inference engines reasoning about the sets of procedural rules. Because of the use of various classes libraries which make this system flexible, we call it a knowledge-based integrated manufacturing flexible simulation system.
An Efficient Parallel Algorithm for Rectangular Packing Based on Bintree Expression
Authors: Wang Aihu , Cha Jianzhong , Wang Jinmin 
Published: February 2021

Abstract
In this paper, a method using bintree structure to express the states of the packing space of rectangular packing is proposed. Through the sequential decomposition of the packing space, the optimal packing scheme of various sized rectangular packing can be obtained by every time putting the optimal piece that satisfies specular conditions toward the current packing space and by locating it at the up-left corner of the current packing space. Different optimal packing schemes that satisfy different demands can be obtained by adjusting the values of the ordering factors KA and KB. A parallel algorithm based on SIMD-CREW shared-memory computer is designed through the analysis of the parallelism of the bintree expression. The whole packing process is clearly expressed by the bintree. The computational complexity of the algorithm is shown to be O(n2logn). Both the experimental results and the comparison with other sequential packing algorithms have proved that the parallel packing algorithm is efficient. What is more, it nearly doubles the problem solving speed.
A Primal-Dual Interior-Point QP Method and its Extension for Engineering Optimization
Authors: Zhang Xiong , Zhou Ji , Yu Jun , Cao Ju 
Published: February 2021

Abstract
Presented in this paper is a primal-dual infeasible-interior-point quadratic programming (QP) algorithm and its extension for nonlinear programming that is suited for engineering design and structural optimization, where the number of variables are very large and function evaluations are computationally expensive. The computational experience in solving both test problems and optimal structural design problems using the algorithm demonstrated that the algorithm finds an approximate optimal solution in fewer iterations and function evaluations, the obtained solution usually is an interior feasible solution, and so the resulting method is very efficient and effective.
Experimental Study of a Variable Pressure Damper on Automotive Valve Motion
Authors: Liou Jin-Jang , Huang Grodrue , Hsu Wensyang 
Published: February 2021

Abstract
A variable pressure damper (VPD) is used here to adjusted the friction force on the valve spring to investigate the relation between the friction force and the valve bouncing phenomenon. The friction force on the valve spring is found experimentally, and the corresponding friction coefficient is also determined.
Dynamic valve displacements at different speeds with different friction forces are calibrated. Bouncing and floating of the valve are observed when the camshaft reaches high speed. From the measured valve displacement, the VPD is shown to have significant improvement in reducing valve bouncing distance and eliminating floating. However, experimental results indicate that the valve bouncing can not be eliminated completely when the camshaft speed is at 2985 rpm.
Flexible Optimization of Machine Products Considering the Working Environment
Authors: Yoshimura Masataka , Nishikawa Takatoshi 
Published: February 2021

Abstract
In order to obtain product designs which enhance the flexibility for change in the working environment of the product, a flexible design optimization method is proposed in which any change is clearly evaluated at the design stage. Here, a criterion of maximization of the flexibility for the product working environment is added to the conventional criteria such as the product performance and the manufacturing cost and a multiobjective optimization problem is formulated. The influence that enhancing flexibility has on the other characteristics is integratedly evaluated by the tradeoff analysis of the Pareto optimum solution set. Then, the preference structure of the decision maker is formulated by the preference function for each evaluative characteristic. The preference functions are interactively modified based on the tradeoff analysis between the evaluative characteristics. The solution most sufficiently reflecting the preference structure of the decision maker is finally determined as the design solution.
A Cubic Spline Algorithm on the Rotation Group Using Cayley Parameters
Authors: Park F. C. , Kang I. G. 
Published: February 2021

Abstract
This article presents a cubic spline algorithm for interpolation on the rotation group SO(3). Given an ordered set of rotation matrices and knot times, the algorithm generates a twice-differentiable curve on SO(3) that interpolates the given rotation matrices at their specified times. In our approach SO(3) is locally parametrized by the Cayley parameters, and the generated curve is cubic in the sense that the Cayley parameter representation is a cubic polynomial. The resulting algorithm is a computationally efficient way of generating bi-invariant (i.e., invariant with respect to choice of both inertial and body-fixed frames) trajectories on the rotation group that does not require the evaluation of transcendental functions, and can also be viewed as an approximation to a minimum angular acceleration trajectory. Because the Cayley parameters provide a one-to-one correspondence between R3 and a dense set of SO(3), the resulting trajectories do not have the “multiple winding” effect that occurs in several existing methods.
Development of CAD System for the Fabrication of LCD/VFD Mask From 2D CAD Data
Authors: Jung Seungwook , Lee Kunwoo , Kim Hoisub 
Published: February 2021

Abstract
In the industry of manufacturing photo mask of Liquid Crystal Display (LCD) or Vacuum Florescent Display (VFD), there have been strong needs for a CAD system of fabricating a pattern mask directly from the CAD data of 2D mask design. This paper presents brief introductions to several algorithms and implementations used in the development of a CAD system for LCD/VFD mask fabrication. For the laser writer, it is simply required to provide the loop information of the pattern shapes. The ray casting algorithm is applied to derive this loop information from the CAD data composed of random vector list. For the photo plotter, the selection of the proper apertures and their plotting paths are derived to expose exact pattern shapes in the shortest time. The idea of Voronoi diagram is used to efficiently obtain an exact aperture path in this study. This paper also features some ideas for automatically detecting and fixing errors of designer’s drawing.
Using Design Capability Indices to Satisfy Ranged Sets of Design Requirements
Authors: Chen Wei , Simpson Timothy W. , Allen Janet K. , Mistree Farrokh 
Published: February 2021

Abstract
For robust design it is desirable to allow the design requirements to vary within a certain range rather than setting point targets. This is particularly important during the early stages of design when little is known about the system and its requirements. Toward this end, design capability indices are developed in this paper to assess the capability of a family of designs, represented by a range of top-level design specifications, to satisfy a ranged set of design requirements. Design capability indices are based on process capability indices from statistical process control and provide a single objective, alternate approach to the use of Taguchi’s signal-to-noise ratio which is often used for robust design. Successful implementation of design capability indices ensures that a family of designs conforms to a given ranged set of design requirements. To demonstrate an application and the usefulness of design capability indices, the design of a solar powered irrigation system is presented. Our focus in this paper is on the development and implementation of design capability indices as an alternate approach to the use of the signal-to-noise ratio and not on the results of the example problem, per se.
Dynamic Simulation for the Structural Integrity of Fluid Filled Thin Walled Tanks Subjected to Impact Loading
Authors: Park S. U. , Gilmore B. J. , Singer R. R. 
Published: February 2021

Abstract
The transport of hazardous materials in truck cargo tanks can cause severe environmental damage as a result of the tank’s failure during a collision. Impact due to collision involves the transient dynamic response of the tank, fluid and their interaction. This paper develops a computational approach to predict the dynamic transient response of the tank shell structure subjected to impact loads during crash accidents. In order to compute the fluid and structure interaction, the finite element formulations for the added mass to the structure are developed and integrated with DYNA3D, the nonlinear dynamic structural finite element code. Thus, the computer based approach provides an efficient design tool for fluid filled thin walled structures in general and cargo tanks subjected to an impact situation. This paper presents the lumping process required by the added mass approach for cargo tanks under impact conditions. The structural integrity performance of cargo tank shell construction is investigated.
Two-Dimensional Packing Problems Using Genetic Algorithms
Authors: Jain Sakait , Gea Hae Chang 
Published: February 2021

Abstract
This paper presents a technique for applying genetic algorithms for the two dimensional packing problem. The approach is applicable to not only convex shaped objects, but, can also accommodate any type of concave and complex shaped objects including objects with holes. In this approach, a new concept of a two dimensional genetic chromosome is introduced. The total layout space is divided into a finite number of cells for mapping it into this 2-D genetic algorithm chromosome. The mutation and crossover operators have been modified and are applied in conjunction with connectivity analysis for the objects to reduce the creation of faulty generations. A new feature has been added to the genetic algorithm(GA) in the form of a new operator called compaction. Several examples of GA based layout are presented.
Design of Multi-Component Structural Systems for Optimal Layout Topology and Joint Locations
Authors: Chickermane Hemant , Gea Hae Chang 
Published: February 2021

Abstract
Structural optimization techniques presently consider the design of only single structural components. However, most real life engineering design problems involve multiple components or structures. It is therefore necessary to have a methodology that can address the design of multi-component systems and generate designs for the optimal layouts of individual structures and locations for interconnections. The interconnections include supports provided by the ground, joints and rigid connections like rivets, bolts, weld between components. While topology optimization of structures has been extensively researched, relatively little work has been done on optimizing the locations of the interconnections. In this research, a method to model and define design domains for the interconnections has been developed. The optimization process redistributes material in the component design domains and locates the connections optimally using an energy criterion. Some practical design examples are used to illustrate the capability of this method.
Dynamic Analysis of Trochoidal-Type Machine
Authors: Li Shuangqing , Shung John B. 
Published: February 2021

Abstract
In a trochoidal-type machine, when the apex seals are replaced by tight running clearances between the rotor and chamber, the friction and wear can be eliminated and thus high efficiency and reliability can be obtained. There are many factors which contribute to the dynamic running clearances. The control of the vibration of the rotor-shaft system is important for the control of the running clearance. This paper studied the dynamics of the rotor-shaft system of a trochoidal-type machine without apex seal. The shaft is lumped as an equivalent system of a mass and a spring. The stiffness of the spring is determined by static equivalence of the two systems. In other words, when the same load is applied, the two systems should have the same displacement. The lumped mass is determined by the dynamic equivalence of the two systems. In other words, the natural frequency of the continuous system with expected mode is equal to the natural frequency of the lumped system. The bearings are modeled as distributed springs and dampers. The coefficients of the springs and dampers are obtained by solving the Reynolds’ equation. The established model can be used to predict the effect of the dynamics of the rotor-shaft system on the running clearances between the rotor and chamber.
Kinematic Sensitivity Analysis of the Spatial Four-Bar Mechanism
Authors: Zou Hong-Liu , Abdel-Malek Karim , Wang Jia-Yi 
Published: February 2021

Abstract
An analytical formulation for computing kinematic sensitivity of the spatial four-bar mechanism is presented. The experimental code developed is used to compute an assembled configuration for the mechanism due to a design variation. The mechanism is modeled into a graph where a body is defined as a node and a kinematic joint is defined as an edge. The spherical joint is cut to convert the model into a spanning tree structure. Cutting an edge introduces the spherical constraint. The variation of this constraint is computed while maintaining the joint-attachment vectors and orientation matrices as variables. The variation of these variables determine the new kinematic design of the system. A recursive formulation is introduced to obtain the state variation of a body in terms of the state variation of a junction body and of the relative coordinates along the chain. The Jacobian matrix is then transformed from Cartesian coordinate space to joint coordinate space using velocity transformation matrices. Kinematic sensitivity analyses due to changing a joint-attachment vector and an orientation are presented.
Design for Manufacturing: Discrete or Continuous Tolerances
Authors: Feng Chang-Xue Jack , Kusiak Andrew 
Published: February 2021

Abstract
Tolerance design provides a common ground for design and manufacturing engineers. It has significant impacts on the quality, cost, and manufacturing lead time of a product. Most of the literature treats tolerances as continuous, thus continuous analytic models of various types are established based upon the discrete tolerances and manufacturing data with the regression method. It’ll be demonstrated in this research that this method will lead to solutions of both mathematical suboptimum and manufacturing infeasibility. This paper proposes using discrete tolerances with an integer programming approach so that solutions of both mathematical optimum and manufacturing feasibility are ensured at the design stage of the product. Numerical examples illustrate the differences between the discrete and continuous tolerance approaches.
The Skew-Symmetric Property of the Newton-Euler Formulation for Constrained Multibody Systems
Authors: Lin Hong-Chin , Lin Tsung-Chieh , Yae KwangHae H. 
Published: February 2021

Abstract
This paper proposes a special form of the recursive Newton-Euler formulation that satisfies the skew-symmetric property, which is a necessary condition to ensure global convergence in a class of regressor-based identification and adaptive control (Slotine, 1987a & 1987b; Craig, 1987). For general multibody systems, such a special form has been developed in a reduced Euler-Lagrange formulation, but not in the Newton-Euler formulation, which has been very popular in the computational analysis of large scale systems. The paper successfully constructs a pair of inertia and Coriolis-centrifugal matrices for a “skew-symmetric” recursive Newton-Euler formulation, which can be used in both dynamics simulations and control applications.
Representation and Mapping of Geometric Dimensions From Design to Manufacturing
Authors: Shah Jami J. , Yan Yong 
Published: February 2021

Abstract
This paper describes the development of a dimension model for use in both design and process planning. The model also facilitates the converting of dimensions and tolerances (D&T) from design models to machining features extracted automatically by feature recognition systems. The model is based on relative degrees of freedom of geometric entities, such as edges and faces of a part. Dimension graphs are created based on the degrees of freedom. The model allows dimension specification, dimension scheme modification, and dimension scheme validation. A methodology to automatically determine the dimensions of machining volumes obtained by volume decomposition is also described.
Hierarchical Solution of Large-Scale Three-Dimensional Topology Optimization Problems
Authors: DeRose Giuseppe C. A. , Díaz Alejandro R. 
Published: February 2021

Abstract
A new solution strategy for topology optimization in 3D elasticity is discussed. This solution strategy uses principles from hierarchical data structures and image analysis to reduce the computational resources necessary to solve large-scale topology optimization problems. The savings in computational resources result from successive use of increasingly detailed hierarchical models starting from a coarse approximation. These models, stored using octree data structures, are used to determine the finite element discretization at a given hierarchy. Through the use of the hierarchical models, large-scale topology optimization problems in 3D elasticity may be solved on desktop workstations.