bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Analysis of Gear Meshing Teeth Using Modified Timoshenko Beam Theory
Authors: Xie M. , Amirouche F. M. L. , Valco M. 
Published: March 2021

Abstract
An explicit dynamical formulation of the gear meshing teeth using modified Timoshenko beam theory is presented in this paper. The acting position direction and magnitude of the external force is assumed time variant. The meshing tooth is modeled as a cantilever beam where the inertia forces due to the large rotation of the tooth base, as well as the external equivalent axial force and moment are all included in the equations of motion. Computer algorithms for gear dynamics based on the theory developed is presented. In the numerical simulations, the involute for the gear tooth profile is considered.
A Study on the Shrinkage Characteristics and Dimensional Accuracy of Cast Gears
Authors: Adjunta Jimmy , Houser Donald 
Published: March 2021

Abstract
This paper is primarily concerned with the evaluation of the dimensional quality of spur gears produced by two casting processes, i. e., the investment casting and v-sand casting processes. The casting patterns used were designed by compensating for process shrinkage, and were manufactured using a flexible CNC gear machining process. A computer program, CASTGR, was written to facilitate the design phase of the patterns. The various gear configurations cast were inspected using an universal coordinate measuring machine. The geometry of the casting and pattern were correlated to verify the contraction characteristics of the gear castings. In an attempt to categorize the precision capabilities of the two casting processes, the spread of the deviations found for tooth thickness measurements and measurements along profiles and leads of the cast gears were examined. The observed effects of other process variables is also included.
BESHOP: A Program Package for Shape Optimization in 2-D Elasticity Problems
Authors: Farshi Behrooz , Moradi Shapour 
Published: March 2021

Abstract
In this paper a package is introduced which handles shape optimization in 2-dimensional elasticity problems where Boundary Element Method is used for the analysis phase affording a large reduction in the problem dimensionality together with a variant of the Method of Center Points for the optimization phase. This optimization method allows a high reduction in the number of constraints considered in each step, as well as low number of cycles, resulting in notable overall efficiency.
Design variables in optimum shape determination consists of basic nodal coordinates for B-spline functions as the means to define smooth boundary curves. Maximum stress and/or displacements at critical boundary points are observed as constraints in each cycle of the procedure.
Three classical case examples are solved successfully, and the results are compared with those of others, illustrating the superior capabilities of the program package.
On Global Feasible Search for Global Design Optimization With Application to Generalized Polynomial Models
Authors: Lo Chihsiung , Papalambros Panos Y. 
Published: March 2021

Abstract
A powerful idea for deterministic global optimization is the use of global feasible search, namely, algorithms that guarantee finding feasible solutions of nonconvex problems or prove that none exists. In this article, a set of conditions for global feasible search algorithms is established. The utility of these conditions is demonstrated on two algorithms that solve special problem classes globally. Also, a new model transformation is shown to convert a generalized polynomial problem into one of the special classes above. A flywheel design example illustrates the approach. A sequel article provides further computational details and design examples.
A Convex Cutting Plane Algorithm for Global Solution of Generalized Polynomial Optimal Design Models
Authors: Lo Chihsiung , Papalambros Panos Y. 
Published: March 2021

Abstract
Global optimization algorithms for generalized polynomial design models using a global feasible search approach was discussed in a previous article. A new convex cutting plane algorithm (CONCUT) based on global feasible search and with improved performance is presented in this sequel article. Computational results of the CONCUT algorithm compared to one using linear cuts (LINCUT) are given for various test problems. Two design examples, a speed reducer and a corrugated bulkhead design, illustrate the application of the algorithms.
Some Further Results for a Reduction Method in Nonhierarchical Optimization-Based Design
Authors: Wu Bi-Chu , Azarm Shapour 
Published: March 2021

Abstract
In a previous article, a new and simple reduction method was presented for optimization-based design of nonhierarchically decomposed engineering systems. As a sequel to that work, in this paper we first examine some significant issues in relation to the reduction method: the optimality conditions when the method is applied, the reason why move limits are not required, and some of the factors that might affect the robustness of the cumulative constraints. For verification and validation, we then present some numerical test results in which the method is applied to twenty-one (21) test problems. Based on the test results reported, some guidelines for applying the method are suggested.
Determination of Significance of Stress Stiffening Effects in Flexible Multibody Dynamic Systems
Authors: Ryu Jeha , Kim Sang Sup , Kim Sung-Soo 
Published: March 2021

Abstract
This paper presents a criterion for determining whether or not a flexible multibody dynamic system reveals stress stiffening effects. In the proposed criterion, the eigenvalue variation that results from adding the modal stress stiffness matrix to the conventional linear modal stiffness matrix is examined numerically before actual dynamic simulation. If the variation is sufficiently large for any flexible body, then stress stiffening effects are said to be significant and must be included in dynamic simulation of flexible multibody systems. Since the criterion uses the most general stress stiffness matrix, which can be represented as a function of applied and constraint reaction loads as well as of a system of 12 inertial loads, this criterion is applicable to any general flexible multibody dynamic systems. Several numerical results are presented to show the effectiveness of the proposed criterion.
A Model for Mechanism Data Storage
Authors: Wang Wan 
Published: March 2021

Abstract
A data model for kinematic structure of mechanisms and its coding principle are proposed, based on the topological graph and contract graph. In the model every basic chain is mapped by a code of 5 decimal digits and a mechanism is mapped by a set of code of basic chains. The model occupies minimal memory, and contains a complete set of useful primary parameters of structure, and significantly reduce computer time for isomorphism identification.
Parametric Surface Intersections for Geometric Modeling
Authors: Chen J.-M. , Wang Yu , Guroz E. L. , Prinz Fritz B. 
Published: March 2021

Abstract
A surface-surface intersection algorithm is an important element in the development of a geometric modeler. This paper presents a new algorithm for calculating the intersection curves of two parametric surfaces. Combining the merits of subdivision and global exploration methods, this algorithm is efficient and robust in dealing with the issues related to small loops and singularities. This algorithm is demonstrated with examples of non-uniform rational B-spline surfaces.
Intersection of Offset Surfaces of Parametric Patches
Authors: Wang Yu 
Published: March 2021

Abstract
In this paper, we present a new method to calculate intersection curve of offset surfaces of two parametric surface patches. This method is based on the concept of normal projection and the intersection problem is formulated with a set of tensorial differential equations. The intersection is represented in the parametric spaces of the base surfaces and no offset surface approximation is needed. Numerical examples are presented for non-uniform rational b-spline (NURBS) surfaces to illustrate the effectiveness and efficiency of the proposed approach.
A Geometric Framework for Optimal Surface Design
Authors: Park Frank C. 
Published: March 2021

Abstract
We present a Riemannian geometric framework for variational approaches to geometric design. Optimal surface design is regarded as a special case of the more general problem of finding a minimum distortion mapping between Riemannian manifolds. This geometric approach emphasizes the coordinate-invariant aspects of the problem, and engineering constraints are naturally embedded by selecting a suitable metric in the physical space. In this context we also present an engineering application of the theory of harmonic maps.
Use of Piezoceramic Actuation for Automotive Active Suspension Mechanisms: A Feasibility Study
Authors: Thirupathi Sridhar R. , Naganathan Nagi G. 
Published: March 2021

Abstract
Active suspension for automobiles involves an active control of wheel motions. This work investigates the possibility of realizing controlled wheel motion for an active suspension using piezoceramic actuation. The proposed concept deviates significantly from conventional practice of using heavier, hydraulic actuators. Rather than accomplising the wheel motion using the direct stroke of an actuator, the motion is to be realized by actively modifying the stiffness of the suspension system using piezoceramic sensing and actuation. Preliminary analysis and experimentation are performed to test the above concept. Two candidate designs are presented for composite piezoceramic suspension elements. It is shown that it is possible to control suspension system deflections through sufficient motion ranges necessary for this application.
Computer Aided Design of Robot Work Cell
Authors: Neogy C. , Mohan S. , Soni A. H. 
Published: March 2021

Abstract
The extensive use of robots in flexible manufacturing systems and other engineered systems has created the need for developing a design tool for workcells in which robots are used. In current practice, the location of a robot within a workcell is determined by evaluating reachability and mobility criteria. Using reachability and mobility criteria, the robot can be located in a wide area within a workcell. In this paper, a computer aided design procedure that addresses the issues of minimum cycle time of the robot, optimum location of the robot within the cell and location of the workstations for time optimal motion, is provided. Significant results for three, four and six workstation cases are presented along with a design procedure for using these results.
A Synthesis Algorithm of Three-Revolute Manipulators by Means of the Workspace Contour Algebraic Formulation
Authors: Ceccarelli Marco 
Published: March 2021

Abstract
A synthesis algorithm of general three-revolute open chain manipulators is proposed making use of an algebraic formulation of the workspace contour, which has been deduced in a previous paper. The algebraic form of the synthesis model allows to formulate some algebraic design equations and to discuss the number and the type of the multiple solutions.
Singularity-Free Evolution From One Configuration to Another in Serial and Fully-Parallel Manipulators
Authors: Innocenti C. , Parenti-Castelli V. 
Published: March 2021

Abstract
Among the several ways adopted for the characterization of manipulator performances is identification of the typologies of maneuvers allowed by the manipulator kinematic arrangement. The multiplicity of configurations corresponding to a given hand position for serial manipulators, or to a given set of input values for fully-parallel manipulators, makes one wonder whether a manipulator can perform the maneuver of changing its configuration without meeting singularities. The paper shows that singularity-free configuration change is possible both for general-geometry serial and fully-parallel architectures. Results are reported that shed light on potential performances of manipulators and allow, in perspective, a deeper exploitation of their structural peculiarities.
Predicting Force Redistributions on Walking Robots for Reliable Locomotion: Modeling and Experiments
Authors: Nagy Peter V. , Desa Subhas , Whittaker William L. 
Published: March 2021

Abstract
A large number of walking robots walk with a statically-stable gait. A statically-stable walker has at least three feet that are in ground contact at any time. If there are more than three feet in ground contact, the normal (vertical) forces exerted by the ground on the feet of the walker are indeterminate, unless they are measured. Some walking robots may walk with more than three legs in ground contact in order to achieve greater stability. To ensure this stability it is desirable to predict how vertical forces passively redistribute underneath the feet during walker motions. Predictions of future foot forces can be used as a basis for accepting or rejecting any planned walker motion. Two methods — the least-squares method and the compliance method — for predicting this redistribution of forces in the face of static indeterminacy are presented in this work. Both methods are computationally efficient, and give reasonably accurate predictions, as verified by experiments on a walking robot.
Design of Articulated Manipulators Based on Kinematic and Dynamic Criteria
Authors: Dwarakanath A. , Ghosal A. , Shrinivasa U. 
Published: March 2021

Abstract
This paper deals with the design of articulated manipulators with joint motion constraints. The aim is to design smaller and lighter robots by taking into account kinematic and dynamic criteria and the application. Painting and welding of large areas are the applications considered for which the end effector carrying the necessary tool should move at a uniform velocity in the work area. Further entire work area and the area required for acceleration and deceleration, must also lie inside the workspace of the manipulator. From kinematic consideration, link dimensions, joint rotation ranges and mean positions are obtained such that the required work area lies inside the workspace. The cross-sectional dimensions of the links are chosen such that the tip deflection under the worst loading conditions is less than a given minimum. The worst loading is obtained by considering the static loads due to weights of payloads, links, actuators and transmission elements and the dynamic loads due to the motion of the links. The torque requirements for a specified process velocity and acceleration depend on the loading and also on the kinematic parameters such as link lengths, joint ranges and mean positions. Hence the link dimensions, joint ranges and mean positions are optimized for minimum torque and the results are compared with those found from purely kinematic considerations.
Link-Centre and Indexes of a Kinematic Chain
Authors: Agrawal V. P. , Yadav J. N. , Pratap C. R. 
Published: March 2021

Abstract
A new graph theoretic concept of link-centre of a kinematic chain is introduced. The link-centre of a kinematic chain is defined as a subset of set of links of the kinematic chain using a hierarchy of criteria based on distance concept. A number of structural invariants are defined for a kinematic chain which may be used for identification and classification of kinematic chains and mechanisms. An algorithm is developed on the basis of the concept of distance and the link-centre for optimum selection of input, output and fixed links in a multi-degree-of-freedom function generator.
Generalized Synthesis of Adjustable Mechanisms
Authors: Chuenchom Tushchai , Kota Sridhar 
Published: March 2021

Abstract
Conventional mechanisms (cams, gears, and linkage-based that are typically single degree of freedom) are being increasingly replaced by multi-degree of freedom multi-actuators integrated with logic controllers. This new trend in sophistication although provides greatly enhanced flexibility, there are many instances where the flexibility needs are exaggerated and the associated complexity is unnecessary. On the other hand, the conventional mechanisms cannot fulfill multi-task requirements due to lack methods to design-in flexibility. Adjustable mechanisms or “programmable” mechanisms provide a cost-effective middle ground between hard automation and overly flexible expensive robots; especially for tasks that demand only limited flexibility. This paper presents a generalized synthesis procedure for designing adjustable robotic mechanisms for path generation. The goal is to develop a methodology to synthesize a single mechanism that can trace a given set of three-dimensional trajectories by simply adjusting one of the mechanism parameters; say the length of a particular link. The synthesis procedure presented in this paper entails coupler curve classification and pattern recognition techniques, eleven precision-point (Burmester theory) synthesis of geared five-bar mechanisms, multi-objective optimization and statistical analysis.
Geometric Construction of Bézier Type Motion Interpolants
Authors: Ge Q. J. , Ravani B. 
Published: March 2021

Abstract
This paper deals with discrete computational geometry of motions and develops geometric construction algorithms for interpolating in-between rigid displacements. It combines concepts from the fields of kinematics and computational geometry and develops a computational framework for constructing motion interpolants useful in mechanical systems animation, robot trajectory planning and key framing in computer graphics.
A de Casteljau type algorithm is presented for constructing Bézier and rational Bézier motion interpolants. In addition, the problem of achieving higher order of continuity in piecing together motion interpolants is studied. A geometric construction algorithm is presented for designing C2 continuous motion interpolants.
Theory on Joint Specifications in the Design of Deployable Truss Structures
Authors: Warnaar D. B. , Chew M. , Olariu S. 
Published: March 2021

Abstract
The inter-connectivity and type selection of joints in a mechanism can be represented by a graph. In this article a technique is presented for the generation of such a graph for a (spatial) deployable truss structure. First a fundamental graph is constructed which reveals all possible joint connections in a deployable structure. This graph, which can be derived from the geometry of a deployable structure, is then reduced to the graph of the kinematic structure (revealing the joint inter-connectivity) by applying a set of rules. The process of joint specification is completed by assigning joint types to edges in the graph such that the required mobility of the deployable structure it represents is ensured. Procedures are provided that incorperate the techniques introduced in this article and which can be used to generate all possible joint assignments for a given deployable structure.
A Method for Detecting Isomorphism in Graphs Using Vertex Degree Correspondence With Partitioning
Authors: Warnaar D. B. , Chew M. , Olariu S. 
Published: March 2021

Abstract
An efficient and accurate procedure is presented for testing pairs of graphs for isomorphism. The procedure determines isomorphism conclusively by partitioning the graphs into sets of vertices of the same degree. Subsequently, isomorphism is proven or disproven through a comparison of the inter-connectivity of the vertices within each set and a comparison of the inter-connectivity between each set. The procedure is tested on large sets of graphs generated using a (novel) technique also introduced in this article. The procedure has shown to be more efficient than previous methods, without compromising its accuracy.
Development of a Standard Code for Colored Graphs and its Application to Kinematic Chains
Authors: Shin Jae Kyun , Krishnamurty Sundar 
Published: March 2021

Abstract
The development of an efficient solution procedure for the detection of isomorphism and canonical numbering of vertices of colored graphs is introduced. This computer based algorithm for colored graphs is formed by extending the standard code approach earlier developed for the canonical numbering of simple noncolored graphs, which fully utilizes the capabilities of symmetry analysis of such noncolored graphs. Its application to various kinematic chains and mechanisms is investigated with the aid of examples. The method never failed to produce unique codes, and is also found to be robust and efficient. Using this method, every kinematic chain and mechanism, as well as path generators and function generators, will have their own unique codes and a corresponding canonical numbering of their respective links. Thus, based on its efficiency and applicability, this method can be used as a universal standard code for identifying isomorphisms, as well as for enumerating nonisomorphic kinematic chains and mechanisms.
An Efficient Method for the Kinematics of Multibody Systems That Works in Singular Positions
Authors: Avello A. , Bayo E. 
Published: March 2021

Abstract
When a multibody system reaches a singular position, one or more degrees of freedom appear instantaneously and the jacobian matrix of the constraint equations becomes rank-deficient. The classical kinematic formulation is based on the factorization of the jacobian and, therefore, fails in singular positions. In this paper we develop an efficient method, which uses a penalty and an augmented Lagrangian formulation, and successfully handles singular positions. This formulation automatically copes with redundant incompatible constraints and guarantees the stability of the constraints during numerical integration. Critical numerical examples are shown which corroborate these findings.
Signal Flow Graphs for Spatial Gear Trains
Authors: Ma R. , Gupta Krishna C. 
Published: March 2021

Abstract
Signal flow graphs (SFG) have been applied in many areas such as circuit analysis, controls, mechanical vibrations, statistics and operations research. They have also been applied to the analysis of planetary gear trains which are planar, i.e. all of the gear axes are parallel. In this paper, signal flow graphs are applied to the spatial planetary gear trains. Some additional terminology and rules which are needed for this important application are developed in this paper and illustrated by examples.
Automated Welding Process Fixture Planning Using Features
Authors: Straus R. J. , Liou F. W. 
Published: March 2021

Abstract
Flexible robotic welding cells have been established as an integral part of manufacturing. In order to plan the entire welding process in the design stage, mathematical modeling of the planning procedure has become very important. Both the geometric and non-geometric representations, such as the geometric description of workpieces, fixtures, and end-effectors and the planning of the welding process, are the key elements to success. Emphasis in this paper is fixture planning, in which an automated fixturing approach is examined to greatly increase workcell flexibility. A feature-based modeling approach is proposed to simulate the fixturing process in an automated welding cell.
Implications of Ergonomic and User Considerations on Manufacturing Consumer Products
Authors: Allada Venkat , Kopardekar Parimal , Anand S. , Mital Anil 
Published: March 2021

Abstract
Most designers do not consider ergonomic guidelines in designing consumer products. Also, very little attention is generally paid to user needs and preferences. It is imperative that consumer products be designed keeping in mind the human capabilities and limitations. Such considerations in the product design process are necessary since the market is becoming competitive and users more picky. The purpose of this paper is to consider the implications of ergonomic design guidelines on consumer product design, its manufacturing, and associated costs. A Linear Programming model is also developed to assist designers in the product design process.