Integration of Geometry and Analysis for Vehicle System Applications: Continuum-Based Leaf Spring and Tire Assembly

2015 ◽  
Vol 11 (3) ◽  
Author(s):  
Zuqing Yu ◽  
Yiguan Liu ◽  
Brian Tinsley ◽  
Ahmed A. Shabana
Keyword(s):  
Computer Aided Design ◽  
Contact Forces ◽  
Leaf Spring ◽  
Dynamic Simulations ◽  
Constraint Equations ◽  
Revolute Joints ◽  
New Models ◽  
Analysis System ◽  
Aided Design ◽  
Algebraic Constraint

The development of new and complex vehicle models using the absolute nodal coordinate formulation (ANCF) and multibody systems (MBS) algorithms is discussed in this paper. It is shown how a continuum-based finite element (FE) leaf spring and tire assembly can be developed at a preprocessing stage and integrated with MBS algorithms, allowing for the elimination of dependent variables before the start of the dynamic simulations. Leaf springs, which are important elements in the suspension system of large vehicles, are discretized using ANCF FEs and are integrated with ANCF tire meshes to develop new models with significant details. To this end, the concept of the ANCF reference node (ANCF-RN) is used in order to systematically assemble the vehicle model using linear algebraic constraint equations that can be applied at a preprocessing stage. These algebraic constraint equations define new FE connectivity conditions that include the leaf spring shackle/chassis assembly, tire flexible tread/rigid rim assembly, tire/axle assembly, and revolute joints between different vehicle components. The approach presented in this paper allows for using both gradient deficient and fully parameterized ANCF FEs to develop the new models. In order to develop accurate leaf spring models, the prestress of the leaves and the contact forces between leaves are taken into consideration in the ANCF models developed in this investigation. Numerical results are presented in order to demonstrate the use of the computational framework described in this paper to build continuum-based leaf spring/tire assembly that can be integrated with complex vehicle models. The results of this paper also demonstrate the feasibility of developing a CAD (computer-aided design)/analysis system in which the geometry and analysis mesh of a complete vehicle can be developed in one step, thereby avoiding the incompatibility and costly process of using different codes in the flexible MBS analysis.

A New Family of Bricard-Derived Deployable Mechanisms

2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Hailin Huang ◽  
Bing Li ◽  
Jianyang Zhu ◽  
Xiaozhi Qi
Keyword(s):  
Large Volume ◽  
Computer Aided Design ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
New Family ◽  
Revolute Joints ◽  
Computer Aided ◽  
Cad Models ◽  
Aided Design

This paper proposes a new family of single degree of freedom (DOF) deployable mechanisms derived from the threefold-symmetric deployable Bricard mechanism. The mobility and geometry of original threefold-symmetric deployable Bricard mechanism is first described, from the mobility characterstic of this mechanism, we show that three alternate revolute joints can be replaced by a class of single DOF deployable mechanisms without changing the single mobility characteristic of the resultant mechanisms, therefore leading to a new family of Bricard-derived deployable mechanisms. The computer-aided design (CAD) models are used to demonstrate these derived novel mechanisms. All these mechanisms can be used as the basic modules for constructing large volume deployable mechanisms.

The Design Of Digital Test Simulator

1992 ◽  
pp. 71-81
Author(s):  
Mohamed Othman ◽  
Bambang Sunaryo Suparjo
Keyword(s):  
Computer Aided Design ◽  
Logic Circuit ◽  
Testability Analysis ◽  
Computer Aided ◽  
Digital Test ◽  
Analysis System ◽  
Aided Design ◽  
Controllability And Observability ◽  
Combinational Logic Circuit ◽  
Pascal Language

Digital Test Simulator is a Computer Aided Design (CAD) tools written in Turbo Pascal language ver. 5.0. It is a gate level simulator to measures the testability values of a combinational logic circuit. It was developed based on the testability analysis system called Computer-Aided MEsurefor LOgic Testability (CAMELOT). The measurement of the testability, controllability and observability for every nodes are based on the topologyical description of the circuit. The final results produced by simulator can be expressed in the form of table and histogram. Comparison of the various nodal testability values allows the areas of poor testability to be readily identified and the inprovement can be done to the circuits to make it more testable. Key Words: Logic circuit; Computer-Aided Design; CAMELOT approach; Digital Test Simulator

Over-Constrained Mechanisms Derived From RPRP Loops

2018 ◽  
Author(s):  
Kwun-Lon Ting ◽  
Kuan-Lun Hsu
Keyword(s):  
Computer Aided Design ◽  
Random Search ◽  
Modular Approach ◽  
Input Output ◽  
Assembly Strategy ◽  
Revolute Joints ◽  
Computer Aided ◽  
Prismatic Joints ◽  
Aided Design ◽  
Four Bar Linkage

This paper addresses the assembly strategy capable of deriving a family of over-constrained mechanisms systematically. The modular approach is proposed. It treats the topological synthesis of over-constrained mechanisms as a systematical derivation rather than a random search. The result indicates that a family of over-constrained mechanisms can be constructed by combining legitimate modules. A spatial four-bar linkage containing two revolute joints (R) and two prismatic joints (P) is selected as the source-module for the purpose of demonstration. All mechanisms discovered in this paper were modeled and animated with computer aided design (CAD) software and their mobility were validated with input-output equations as well as computer simulations. The assembly strategy can serve as a self-contained library of over-constrained mechanisms.

Overconstrained Mechanisms Derived From RPRP Loops

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Kuan-Lun Hsu ◽  
Kwun-Lon Ting
Keyword(s):  
Computer Aided Design ◽  
Random Search ◽  
Modular Approach ◽  
Input Output ◽  
Assembly Strategy ◽  
Revolute Joints ◽  
Prismatic Joints ◽  
Overconstrained Mechanisms ◽  
Aided Design ◽  
Four Bar Linkage

This paper addresses the assembly strategy capable of deriving a family of overconstrained mechanisms systematically. The modular approach is proposed. It treats the topological synthesis of overconstrained mechanisms as a systematical derivation rather than a random search. The result indicates that a family of overconstrained mechanisms can be constructed by combining legitimate modules. A spatial four-bar linkage containing two revolute joints (R) and two prismatic joints (P) is selected as the source-module for the purpose of demonstration. All mechanisms discovered in this paper were modeled and animated with computer-aided design (CAD) software and their mobility were validated with input–output equations as well as computer simulations. The assembly strategy can serve as a self-contained library of overconstrained mechanisms.

Ideal Compliant Joints and Integration of Computer Aided Design and Analysis

2014 ◽  
Author(s):  
Ashraf M. Hamed ◽  
Paramsothy Jayakumar ◽  
Michael D. Letherwood ◽  
David J. Gorsich ◽  
Antonio M. Recuero ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Large Scale ◽  
Algebraic Equations ◽  
B Spline ◽  
Constraint Equations ◽  
Compliant Joints ◽  
Linear Algebraic Equations ◽  
Dependent Variables ◽  
Computer Aided ◽  
Aided Design

This paper discusses fundamental issues related to the integration of computer aided design and analysis (I-CAD-A) by introducing a new class of ideal compliant joints that account for the distributed inertia and elasticity. The absolute nodal coordinate formulation (ANCF) degrees of freedom are used in order to capture modes of deformation that cannot be captured using existing formulations. The ideal compliant joints developed can be formulated, for the most part, using linear algebraic equations, allowing for the elimination of the dependent variables at a preprocessing stage, thereby significantly reducing the problem dimension and array storage needed. Furthermore, the constraint equations are automatically satisfied at the position, velocity, and acceleration levels. When using the proposed approach to model large scale chain systems, differences in computational efficiency between the augmented formulation and the recursive methods are eliminated, and the CPU times resulting from the use of the two formulations become similar regardless of the complexity of the system. The elimination of the joint constraint equations and the associated dependent variables also contribute to the solution of a fundamental singularity problem encountered in the analysis of closed loop chains and mechanisms by eliminating the need to repeatedly change the chain or mechanism independent coordinates. It is shown that the concept of the knot multiplicity used in computational geometry methods, such as B-spline and NURBS (Non-Uniform Rational B-Spline), to control the degree of continuity at the breakpoints is not suited for the formulation of many ideal compliant joints. As explained in this paper, this issue is closely related to the inability of B-spline and NURBS to model structural discontinuities. Another contribution of this paper is demonstrating that large deformation ANCF finite elements can be effective, in some MBS application, in solving small deformation problems. This is demonstrated using a heavily constrained tracked vehicle with flexible link chains. Without using the proposed approach, modeling such a complex system with flexible links can be very challenging. The analysis presented in this paper also demonstrates that adding significant model details does not necessarily imply increasing the complexity of the MBS algorithm.

Ideal Compliant Joints and Integration of Computer Aided Design and Analysis

2015 ◽  
Vol 10 (2) ◽  
Author(s):  
Ashraf M. Hamed ◽  
Paramsothy Jayakumar ◽  
Michael D. Letherwood ◽  
David J. Gorsich ◽  
Antonio M. Recuero ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Processing Unit ◽  
B Spline ◽  
Constraint Equations ◽  
Central Processing ◽  
Compliant Joints ◽  
Linear Algebraic Equations ◽  
Dependent Variables ◽  
Computer Aided ◽  
Aided Design

This paper discusses fundamental issues related to the integration of computer aided design and analysis (I-CAD-A) by introducing a new class of ideal compliant joints that account for the distributed inertia and elasticity. The absolute nodal coordinate formulation (ANCF) degrees of freedom are used in order to capture modes of deformation that cannot be captured using existing formulations. The ideal compliant joints developed can be formulated, for the most part, using linear algebraic equations, allowing for the elimination of the dependent variables at a preprocessing stage, thereby significantly reducing the problem dimension and array storage needed. Furthermore, the constraint equations are automatically satisfied at the position, velocity, and acceleration levels. When using the proposed approach to model large scale chain systems, differences in computational efficiency between the augmented formulation and the recursive methods are eliminated, and the central processing unit (CPU) times resulting from the use of the two formulations become similar regardless of the complexity of the system. The elimination of the joint constraint equations and the associated dependent variables also contribute to the solution of a fundamental singularity problem encountered in the analysis of closed loop chains and mechanisms by eliminating the need to repeatedly change the chain or mechanism independent coordinates. It is shown that the concept of the knot multiplicity used in computational geometry methods, such as B-spline and NURBS (nonuniform rational B-spline), to control the degree of continuity at the breakpoints is not suited for the formulation of many ideal compliant joints. As explained in this paper, this issue is closely related to the inability of B-spline and NURBS to model structural discontinuities. Another contribution of this paper is demonstrating that large deformation ANCF finite elements can be effective, in some multibody systems (MBS) applications, in solving small deformation problems. This is demonstrated using a heavily constrained tracked vehicle with flexible-link chains. Without using the proposed approach, modeling such a complex system with flexible links can be very challenging. The analysis presented in this paper also demonstrates that adding significant model details does not necessarily imply increasing the complexity of the MBS algorithm.

Computer Aided Design of Architecture Engineering Based on Mathematical Model of AHP

2014 ◽  
Vol 556-562 ◽  
pp. 877-880
Author(s):  
Tao Meng
Keyword(s):  
Data Analysis ◽  
Computer Aided Design ◽  
Management System ◽  
Visual Display ◽  
Matlab Software ◽  
Construction Engineering ◽  
Analysis System ◽  
Display Window ◽  
Aided Design ◽  
Bidding Process

In this paper we introduced AHP method in bidding management of construction engineering, and use the MATLAB software to establish the bidding computer analysis system. This paper expounds AHP of the construction bidding process, and design AHP of computer bidding management system according to it. In order to verify the applicability of the model in bidding management system, we use MATLAB software to design bidding data analysis and simulation experiment of the construction. Through the calculation we obtain MATLAB visual display window of bid data analysis. At 50 steps, the convergence residual is, which meets the design requirement of accuracy. It provides a theoretical reference for the bidding management of construction process.

A database of finite element models and simulation systems for transporting sheets of paper

2009 ◽  
Vol 224 (8) ◽  
pp. 1783-1793
Author(s):  
H Cheng ◽  
K Yoshida ◽  
S Noro ◽  
J Tamamoto ◽  
M Asada
Keyword(s):  
Finite Element ◽  
Computer Aided Design ◽  
Fe Simulation ◽  
Simulation System ◽  
Finite Element Models ◽  
Design Tools ◽  
Efficient Calculation ◽  
Analysis System ◽  
Aided Design ◽  
Simulation Systems

Machines used for handling flexible sheets of paper may easily undergo jams due to the existence of irregular conditional sheets. However, most of the studies on handling behaviours have only been done for general sheets of paper transported with some simple guides. Establishing an efficient calculation method and analysis system that can predict all kinds of sheets whether or not there is jam in transport guides becomes more and more important. In this article, based on an analysis of the transport of a head-folded sheet in a V-type guide both in the experi-ment and finite-element (FE) simulation, the method of building the database of FE models for conditional sheets is established. A simulation system that directly connects the computer-aided design tools and the established database is also developed. Some simulated examples of sheet handling behaviours are demonstrated. It is shown that the developed system is useful for designing any transport guide.

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