bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design for Energy Absorption: A Topology Optimization Approach
Authors: Gea Hae Chang , Luo Jianhui 
Published: November 2020

Abstract
Topology optimization for energy absorption is studied in this paper. Unlike conventional mean compliance formulation, this paper considers two main functions of vehicle structure: stiffness and energy absorption. During its normal usages, stiffness is chosen as the design objective. During impact, portion of vehicle structures absorbs impact energy while other part maintains the structural integrity. Therefore, we implemented a regional strain energy formulation to topology optimization. Sensitivity for regional strain energy is derived from the adjoint method. Numerical results from the proposed formulation are presented.
Perfect Static Balance With Normal Springs
Authors: te Riele Freek L. S. , Herder Just L. 
Published: November 2020

Abstract
In biomechanical engineering, gravity balancers are often used in orthoses carrying the weight of paralyzed limbs. In these applications, simplicity is an insuperable demand. However, known gravity balancers do not combine simplicity with perfect balance. This paper describes several gravity equilibrators providing perfect static balance. As opposed to many known solutions, the proposed balancers incorporate normal off-the-shelf springs, rather than the zero-free-length springs (springs with a length equal to zero when not preloaded or loaded externally) usually employed. The conceptional synthesis is presented, dimensional design criteria are derived, and prototypes are shown. Based on the prototype’s working principle, an ankle prosthesis, which stabilizes the patient, will be developed.
Development of 5mm-Trocar Laparoscopic Forceps With Mechanical Force Feedback
Authors: van der Pijl Albert J. , Herder Just L. 
Published: November 2020

Abstract
In minimally invasive surgery, surgeons are deprived of direct contact with the patient’s tissue. All manipulation, including diagnostic palpation, is carried out via long and slender instruments, inserted through small trocars inserted in the skin. Due to poor mechanical characteristics, such as internal friction, backlash, and non-linear force transmission functions, current instruments allow only marginal force feedback. Consequently, surgeons lack a major source of vital information, resulting in reduced safety and grasping forces far greater than necessary. Previous research lead to the design of a 10mm-trocar grasper with low friction and an outstanding force transmission characteristic. The present study was conducted to develop this prototype into a clinically applicable instrument which can be used in 5mm-trocar therapy, by redesigning the mechanism while maintaining the excellent mechanical characteristics. This resulted in a clinical prototype, still according the patented rolling link design but in a different embodiment, now also matching the additional specifications. Mechanical testing showed that the mechanical efficiency of the 5mm-trocar version is as high as in the original version. The 5-mm-version will now be used for further optimization and clinical testing.
CyberAgent: Collaborative Agents for Distributed Applications Over the Internet
Authors: Shi J. , Huang G. Q. , Mak K. L. 
Published: November 2020

Abstract
This paper is mainly concerned with developing the broking agents called CyberAgent for collaborations among distributed applications over the Internet. Based on a flexible relationship model — CyberWorkflow — among CyberAgents, parameters can be transferred among applications with dataflows between CyberAgents, and applications are to be activated sequently according to controlflows among CyberAgents. Details of CyberAgent and CyberWorkflow are discussed in this paper. A case study is introduced in this paper to demonstrate how eight CyberAgents can be used in a Lucas DFA application suit to facilitate collaborations among eight sub-applications, each one occupying an individual CyberAgent. Concluding discussion is provided at the end of this paper.
A Dedicated CAD/CAM System for 5-Axis Machining of Marine Propeller
Authors: Youn Jae-Woong , Jun Yongtae , Park Sehyung 
Published: November 2020

Abstract
The manufacture of a marine propeller typically requires long lead-time to generate 5-axis tool paths. It usually takes several days to manufacture a satisfactory propeller with a general purpose CAD/CAM system. This paper proposes a novel methodology for tool path generation of 5-axis machining of marine propellers. Using the geometric characteristics of propellers, the system first computes check vectors and then generates interference-free tool paths. An iterative NURBS modeling technique is used to improve the accuracy of the models and to increase the productivity. The system has been implemented with C++ and OpenGL graphic library on the Windows system. The system validation and sample results are also given and discussed.
Effectiveness of Neural Network and Genetic Algorithm in Hull Form Design
Authors: Khondoker M. Reaz H. , Rahman Chowdhury Mofizur , Islam Mohammad Mahfuzul 
Published: November 2020

Abstract
This paper aims at developing a fully automated hull form design technique employing an Neural Network and Genetic Algorithm methods resulting in accelerated convergence. For generating an input data that will be, by and large, a close relative of the desired hull, a linear relation has been assumed between the half breadth of different sections and principal dimensions (length, breadth, draft or (displacement)1/3) of a particular type of vessel. Compared to starting with a random value of the input, this technique resulted in faster convergence. The weight matrix for each of these parameters is produced from data obtained from the population. The half-breadth table for a new vessel can be obtained by multiplying the weight matrix with corresponding parameter. However, the half-breadth table obtained in such way may not provide the required displacement and speed of the vessel. Therefore, some readjustments of some of the principal dimensions are required. Neural Networks (Wasserman, 1989) has been used to find the required values of such improved design parameters (principal dimensions). The final design process consists of searching for the exact solution by examining several generations generated by the GA (Goldberg, 1989). The convergence criterion is the summed offset error, which is to be within the envelope defined by the tolerances. Since GA doesn’t guarantee fairness of the surface of the hull form, B-spline curve fitting method is used to obtain a fair hull. Thus, the hull form generated through this process is fully automated, accurate and having fair surface. The technique is also found to be an efficient one.
A Study on Shape Optimization Using Affine Transformation
Authors: Kitayama Satoshi , Yamakawa Hiroshi 
Published: November 2020

Abstract
This paper presents a new method to determine an optimal shape using affine transformation which is used in the field of Computer Aided Design (CAD), linear programming, and etc. We use affine transformation as coordinate transformation. Affine transformation is a linear transformation, so that shapes transformed must be linearly.
Shape optimization of a inclined beam for example, we can deal with in the following manner. We define a simple cantilever beam first in initial design domain, and calculate an optimal shape. Then we use affine transformation remaining with optimal shape calculated in simple design domain and get to an optimal shape of the inclined beam. To compare with an optimal shape obtained by our proposed method, we calculate an optimal shape directly by conventional method in the same design domain after coordinate transformation. We show that affine transformation plays a role as scaling to structural optimization by finite element method and that necessary and sufficient conditions between design variables and shape transformation matrix may exist to get an exact optimal shape. We treat some numerical examples by our proposed method. In numerical examples, we consider shape optimization of inclined cantilever beam for simplicity. We show that some stepwise linear optimal shapes could be expressed from an optimal shape of a simple cantilever beam by using affine transformation. Optimal shape calculated by our method can obtain easily and speedy. Through some numerical examples, we could examine effectiveness of our proposed method.
Large Deformation Behavior of Compliant Mechanisms
Authors: Joo Jinyong , Kota Sridhar , Kikuchi Noboru 
Published: November 2020

Abstract
This paper presents a non-linear formulation for size and shape optimization of compliant mechanisms using tapered beam elements. Designs based on linear and nonlinear formulations are compared using a stroke amplification mechanism example. Also, the scaling effect of the compliant mechanism is investigated.
A Robot for Hand Rehabilitation: A Continuation of the MIT-MANUS Neuro-Rehabilitation Workstation
Authors: Jugenheimer Kristin A. , Hogan Neville , Krebs Hermano I. 
Published: November 2020

Abstract
A novel robot for hand rehabilitation is described. The robot is a continuation of the work done with MIT-MANUS, a robot-aided neuro-rehabilitation workstation. Flexure bearings are used in conjunction with a cable-drive transmission system. The requirements of the robot and key design elements are described. We are presently completing assembly and should commence shortly with system characterization and clinical testing.
Design of Passive Reconfigurable Manipulation Assistive Aids
Authors: Nie Xichun , Krovi Venkat 
Published: November 2020

Abstract
Multi-jointed mechanical systems typically possess excess degrees-of-freedom, which often are neither required nor used in performing typical manipulation tasks. These excessive degrees of freedom then need to be reduced by application of constraints, either actively by suitable control or passively in hardware, prior to task performance.
Our interest is in creating articulated manipulation assistive aids, which combine the motion flexibility due to the multiple articulations with the simplicity of reduced degree-of-freedom control and actuation due to the presence of hardware mechanical constraints.
Specifically we investigate the process of design and prototyping of such reduced-degree-of-freedom manipulators to closely approximate desired planar paths. We then examine design enhancements to permit easy reconfiguration for different sets of paths. Finally, special attention is paid to the creation of a prototype with the ability to be reconfigured for multiple sets of paths, by a controlled variation of the principal structural parameters.
Formulation of Dynamic Loads Generated by Lubricated Journal Bearings
Authors: Alshaer B. J. , Lankarani H. M. 
Published: November 2020

Abstract
This paper addresses the analytical evaluation of dynamic pressures and forces produced by the lubricant in a lubricated long journal bearing under dynamic loading. An evaluation of accuracy of the widely adopted Ott’s solution is conducted. The results show that when the journal center is moving toward the center of the bearing and the eccentricity ratio is high, the force formulation according to Ott’s solution give inaccurate results. Differences as high as 93% is found between Ott’s analytical solution and the numerical solution for certain conditions. Starting from Reynolds partial differential equation of lubrication theory, a new formulation for the dynamic characteristics of lubricated long journal bearing under dynamic loading is presented. The analytical integrations were conducted utilizing the Sommerfeld variable. The lubricant forces calculated at certain instants of time showed exact match with the numerical solution, which is not the case with Ott’s solution. The pressure distribution in the new formulation showed a slight difference compared to the Ott’s solution. The methodology presented in the new formulation to calculate the zero pressure angles at any instant of time showed exact match with the numerical results regardless of sharp changes in the pressure between the positive and negative regions. The new formulation is utilized in evaluating the transient and steady state characteristics of lubricated long journal bearing under unidirectional constant load and the results arc compared with the Ott’s solution.
Dynamics of a Multibody Mechanical System With Lubricated Long Journal Bearings
Authors: Alshaer B. J. , Lankarani H. M. , Shivaswamy S. 
Published: November 2020

Abstract
Clearances exist in different kinds of joints in multibody mechanical systems, which could drastically affect the dynamic behavior of the system. If the joint is dry with no lubricant, impact occurs, resulting in wear and tear of the joint. In practical engineering design of machines, joints are usually designed to operate with some lubricant. Lubricated journal bearings are designed so that even when the maximum load is applied, the joint surfaces do not come into contact with each other. In this paper, a general methodology for modeling lubricated long journal bearings in multibody mechanical systems is presented. This modeling utilizes a new method of solving for the forces produced by the lubricant in a dynamically loaded long journal bearing. A perfect revolute joint in a multibody mechanical system imposes kinematic constraints, while a lubricated journal bearing joint imposes force constraints. As an application, the dynamic response of a crank-slider mechanism including a lubricated journal bearing joint between the connecting rod and the slider is considered and analyzed. The dynamic response is obtained by numerically solving the constraint equations and the forces produced by the lubricant simultaneously with the differential equations of motion and a set of initial conditions numerically. The results are compared with the previous studies performed on the same mechanism as well a dry clearance joint. It is shown that in a multibody mechanical system, the journal bearing lubricant introduces damping and stiffness to the system. The earlier studies previous predict that the order of magnitude of the reaction moment is twice that of a perfect revolute joint. The proposed model predicts that the reaction moment is within the same order of magnitude of the perfect joint simulation case.
Effective Generation of Pareto Sets Using Genetic Programming
Authors: Eddy John , Lewis Kemper 
Published: November 2020

Abstract
Many designers concede that there is typically more than one measure of performance for an artifact. Often, a large system is decomposed into smaller subsystems each having its own set of objectives, constraints, and parameters. The performance of the final design is a function of the performances of the individual subsystems. It then becomes necessary to consider the tradeoffs that occur in a multi-objective design problem.
The complete solution to a multi-objective optimization problem is the entire set of non-dominated configurations commonly referred to as the Pareto set. Common methods of generating points along a Pareto frontier involve repeated conversion of multi-objective problems into single objective problems using weights. These methods have been shown to perform poorly when attempting to populate a Pareto frontier. This work presents an efficient means of generating a thorough spread of points along a Pareto frontier using genetic programming.
Automatic Synthesis of Cooling System Design for Plastic Injection Mould
Authors: Li C. L. 
Published: November 2020

Abstract
This paper reports an automatic algorithm that synthesizes the design of cooling system for plastic injection mould. Automation in cooling system design is an important research area that has not received much attention. In the proposed method, a building block approach to design synthesis is adopted. Given a plastic part and a library of pre-defined cooling sub-systems, the algorithm first decomposes the part into features known as cooling features. For each cooling feature, the corresponding cooling sub-systems are retrieved from the library. The cooling sub-systems are then modified and combined into an initial design of the cooling system for the entire plastic part. The performance of the initial design is verified by using CMold analysis. A design synthesis program has been implemented and an example is given to illustrate the feasible of the proposed algorithm.
Support Structures Extraction for Hybrid Layered Manufacturing
Authors: Ruan Jianzhong , Zhang Jun , Liou F. W. 
Published: November 2020

Abstract
In a multi-axis metal hybrid layered manufacturing system, a combined laser material deposition and material removal system with more than 3-aixs mobility, sometimes support structures are necessary in the part building process, which prevent object from falling during deposition process. Since the support material is the same as build material, it is very difficult to remove the support material in the post processing stage. Thus, the support material must be machined off. Therefore, the geometry information of support structures is important for the machining process. In this paper, a method is presented to extract support structures automatically. Two types of support structures, trapped and non-trapped, are classified in this paper and their extraction methods are discussed respectively.
Promoting Modularity in Evolutionary Design
Authors: Lipson Hod , Pollack Jordan B. , Suh Nam P. 
Published: November 2020

Abstract
Evolutionary design systems apply principles inspired from biological evolution to automate machine design. These systems have been shown to generate simple designs for simple tasks — but their practical ability to scale up to higher complexities remains questioned. One of the keys to accomplishing higher-level evolutionary design is the ability of the process to identify and reuse knowledge discovered at lower levels, thus scaling its search capacity. One way to capture this knowledge is in the form of reusable building blocks — modules. In this paper we define modularity and discuss several approaches to promoting modularity in evolutionary design systems. In particular, we propose a new mechanism that can enhance modularization. This mechanism is based on the observation that designs that exhibit modularity have higher adaptability and consequently have better survival rates under changing requirements. Contrary to other techniques, this is a weak (indirect) formulation that docs not require representation of partial solutions or definition of a genotype from which a design is developed. We demonstrate this principle on an abstract general design problem on which modularity can be statistically quantified.
Tool Path Generation Based on B-Spline Wavelets
Authors: Narayanaswami Ranga , Pang Junhua 
Published: November 2020

Abstract
Tool path generation is a fundamental problem in numerical control machining. Typical methods used for machining 2.5D objects include generation of offset contours using trimmed offset curves and zigzag sequences. The offset contours result in unnecessary detailed curves far away from the object boundary. The zigzag sequences result in frequent stops and changes in tool direction. In this paper we present a novel approach for tool path generation based on wavelet theory. The theory of wavelets naturally leads to a simple cut sequence algorithm that provides valid and efficient coverage of the machined surface. The classical analytical and algebraic complexity in tool path planning is also reduced. In this paper, curves are represented by endpoint interpolating B-splines and their corresponding wavelets. Design and manufacturing examples are also presented in this paper.
A Direct Statistical Formulation to Account for Uncertainty in Mechanical Design: Proof-of-Concept
Authors: Brindavan Hemanthkumar , Ogot Madara 
Published: November 2020

Abstract
In recent years there has been an increased need to account for uncertainty in design as industry strives to reduce the amount of physical prototyping in favor of faster and cheaper computer simulations. Traditionally, incorporation of uncertainty in design models has been achieved mainly through either Monte Carlo simulations or Mean Value (MV) approximations. The former, while relatively accurate, can be computationally prohibitive. MV approximations on the other hand, trade accuracy for higher computational speed. The proposed direct statistical formulation is a Corrected Mean Value (CMV) approximation. The CMV exploits the correlation between the parameter coefficients of variation and the fractional error incurred using the MV approach to determine appropriate correction factors. Multiplication of the MV approximation by the correction term significantly reduces the error, without sacrificing computational speed. The approach therefore presents a more accurate approximation of the expected value of a function. This paper presents a numerical proof-of-concept of the CMV formulation. Several examples are presented to illustrate the efficacy of the proposed methodology.
Three-Equation Kinematic Models for the Human Knee Passive Motion Simulation
Authors: Di Gregorio Raffaele , Parenti-Castelli Vincenzo 
Published: November 2020

Abstract
Mathematical models are essential tools in the functional analysis of complicated biological structures such as the human knee joint. This paper presents two new mathematical models of the human knee for passive motion simulation. Both models comprise three scalar equations in four unknowns that can be reduced to one univariate polynomial equation, when a value of the mechanism’s generalized coordinate is given. The polynomial equation admits at most forty real solutions. Finally, the relationships to transform the employed joint coordinates into the joint coordinates usually employed in clinical practice are also reported.
Stable Evaluation of Probabilistic Constraint in Reliability-Based Design Optimization for Large Deformation Problem
Authors: Park Young H. 
Published: November 2020

Abstract
In this paper, Reliability-Based Design Optimization (RBDO) is carried out using two distinct ways, the Reliability Index Approach (RIA) and the Performance Measure Approach (PMA). It has been theoretically explained that RIA shows instability but PMA is stable and efficient in identifying a probabilistic failure mode in the RBDO process. The PMA is compared to RIA with regard to the stable evaluation of a probabilistic constraint in the RBDO using a large deformation problem. In addition, an efficient Design Sensitivity Analysis (DSA) method is developed to support reliability analysis and reliability-based optimization for a hyper-elastic structure with factional contact using a meshfree method. A numerical result is presented to demonstrate the comparative study between RIA and PMA.
Concept Development of a Tie-Down Temporary Concrete Barrier System
Authors: Bielenberg Robert W. , Reid John D. 
Published: November 2020

Abstract
Design for safety includes not only the vehicle and occupant protection system but also the structures that vehicles hit. One such example includes temporary concrete barriers. Often in work zones on bridges there is very little room available for barrier deflections when impacted by errant vehicles. Thus, deflections of the barriers must be severely restricted to prevent the barrier from being deflected off of the deck, followed closely by the striking vehicle.
A tie-down design was generated consisting of a steel base plate with two vertical steel tubes, each with a crosshead tube blockout. Nonlinear finite element analysis of the new design focused on gauging the performance of the design as well as optimizing the structural requirements and anchor loads. Results of simulating a full-scale crash test predicted that the proposed design would be capable of safely constraining the barriers during an impact event.