bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrating Active-Passive Hybrid Piezoelectric Networks With Active Constrained Layer Treatments for Structural Damping
Authors: Tsai M. S. , Wang K. W. 
Published: March 2022

Abstract
The goals of the research reported in this paper are to investigate the feasibility of integrating Active-Passive Hybrid Piezoelectric Networks (APPN) with the Active Coristrained Layer (ACL) or Enhanced Active Constrained Layer (EACL) treatments, identify the benefits or limitations of the approach, and provide insights toward designing such systems. It is shown that integration of APPN with ACL cannot obtain much extra damping because of low inverse transmissibility, while the APPN-EACL configuration can achieve high damping around the shunt frequency. The APPN-EACL can be synthesized to outperform the APPN, EACL and APPN-ACL configurations under both narrowband and broadband excitations. The study indicates that while EACL can outperform ACL when the demand on performance is high, it will become less effective than ACL when control effort is very limited. However, with the help of the shunt circuit, APPN-EACL can outperform the APPN-ACL system even when the limitation on control effort is high.
Localization of Vibration Propagation in Randomly Disordered Weakly Coupled Two-Dimensional Cantilever-Spring Arrays
Authors: Xie Wei-Chau 
Published: March 2022

Abstract
In this paper, the method of regular perturbation for a linear algebraic system is applied to study localization of vibration propagation in randomly disordered weakly coupled two-dimensional cantilever-spring arrays under external harmonic excitations. Iterative equations are obtained to express the displacement vector of the cantilevers on the Mth “layer” in the Mth-order perturbation in terms of those on the (M − 1)th “layer” in the (M − 1)th-order perturbation. Localization factors, which characterize the average exponential rates of decay of the amplitudes of vibration, are defined in terms of the angles of orientation. First-order approximate results of the localization factors are obtained using a combined analytical-numerical approach. The localization factors are symmetric about the horizontal and vertical axes passing through the cantilever that is being externally excited. For the systems under consideration, the direction in which vibration is dominant corresponds to the smallest localization factor; whereas the “diagonal” directions correspond to the largest localization factor.
P-Bifurcations in the Stochastic Version of the Duffing-van der Pol Equation
Authors: Liang Yan , Namachchivaya N. Sri 
Published: March 2022

Abstract
In this paper, we shall re-examine the stochastic version of the Duffing-van der Pol equation. As in [2], [9], [19], [22], we shall introduce a multiplicative and an additive stochastic excitation in our case, i.e.x¨=(α+σ1ξ1)x+βx˙+ax3+bx2x˙+σ2ξ2, where, α and β are the bifurcation parameters, ζ1 and ζ2 are white noise processes with intensities σ1 and σ2, respectively. The existence of the extrema of the probability density function is presented for the stochastic system. The method used in this paper is essentially the same as what has been used in [19]. We first reduce the above system to a weakly perturbed conservative system by introducing an appropriate scaling. The corresponding unperturbed system is then studied. Subsequently, by transforming the variables and performing stochastic averaging, we obtain a one-dimensional Itv equation of the Hamiltonian H. The probability density function is found by solving the Fokker-Planck equation. The extrema of the probability density function are then calculated in order to study the so-called P-Bifurcation. The bifurcation pictures for the stochastic version Duffing-van der Pol oscillator with a = −1.0, b = −1.0 over the whole (α, β)-plane are given. The related mean exit time problem has also been studied.
Stochastic and Resonant Layers in a Periodically Driven Pendulum
Authors: Luo Albert C. J. , Han Ray P. S. 
Published: March 2022

Abstract
The stochastic and resonant layers in a periodically driven pendulum are investigated in this paper. The analytical solutions and nonlinear natural frequencies of the non-driven pendulum are first derived, and then the energy increments in the stochastic and resonant layers for the driven pendulum are approximated by the work done by the external excitation along the heteroclinic and resonant orbits, respectively. From these results, the approximate analytical conditions for the predictions of stochastic and resonant layers are constructed. Based on these conditions, input parameters are computed for the numerical simulations of the stochastic and resonant layers. The stochastic and resonant layers associated with the librational and rotational motions are illustrated via the Poincare mapping sections.
An Experimental Study About the Bouncing Vibration of a Contact Slider
Authors: Ono Kyosuke , Maruyama Hideki 
Published: March 2022

Abstract
In this paper, we described an experimental study about the fundamental characteristics of the bouncing vibration of contact slider which is composed of a small stainless steel suspension and a glass or lead ball. The behavior of the contact slider was analyzed by using a laser doppler vibrometer. We found that the bouncing vibration was always low when the slider load was large, the coefficient of restitution was low and the suspension damping was high. For lead contact sliders that had a low coefficient of restitution, smaller mass can reduce the bouncing vibration more than the larger mass can. On the other hand, for glass sliders with a high coefficient of restitution, larger mass can reduce the bouncing vibration due to the increase in the inertia effect. Almost all of our experimental results agreed qualitatively with our analytical ones.
Fast Seek Servo Method Using Two-Degree-of-Freedom Control for Magneto-Optical Disk Drives
Authors: Toyama Souichi , Yanagihara Norihisa , Saegusa Shozo , Saito Atsushi 
Published: March 2022

Abstract
The seek speed of magneto-optical disk drives is greater than that of other optical disk drives. To design a high-speed seek servo system that will be an improvement over the traditional system, we must achieve following two goals. One is to drive the coarse-positioning actuator as fast as possible. The other is to restrain shift and vibration of the lens during the seek. We propose to apply two-degree-of-freedom (2-DOF) seek-velocity control and lens-shift restriction control. The 2-DOF seek-velocity control uses acceleration feedforward of the lens motion as well as target velocity signal of the lens velocity. This method can work the coarse actuator quickly. Further, the lens-shift restriction control uses the controlling input to cancel the inertial force that acts on the lens during the seek. By simulating this method, we discovered that such control systems provide the prospect of average seek time shorter than 19 ms.
Acoustic Identification of a Spun Cone Roller Bearing Defect
Authors: Anderson Gerald B. , Smith Richard L. 
Published: March 2022

Abstract
For Several years, the Association of American Railroads (AAR) has been developing new techniques to detect defective roller bearings as part of their new generation wayside acoustic detector program. This paper discusses data collected from several bearings with spun cone defects under both laboratory and simulated revenue service environments. The AAR performed the laboratory tests in July 1996 and the simulated revenue service test was completed in November 1996. Of all bearing defect types to be detected, the most challenging and highest priority is that of a bearing with a loose inner raceway (spinning cone) which rotates about the axle mount. Normal roller bearings have “press fit” inner raceways which keep them from rotating or sliding about the axle. The “Spun Cone” bearing defect is responsible for many of today’s bearing related derailments.
Application of the

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COBRA/TRAC Best Estimate Methodology to the AP600 Large-Break LOCA Analysis
Authors: Zhang Jinzhao , Bajorek S. M. , Kemper R. M. , Nissley M. E. , Petkov N. , Hochreiter L. E. 
Published: March 2022

Abstract
The AP600 is a simplified advanced pressurized water reactor (PWR) design incorporating passive safety systems that perform the same function as the active emergency core cooling systems (ECCSs) on the current reactors. In order to verify the effectiveness of the AP600 design features for mitigation of a postulated large-break loss-of-coolant accident (LOCA), the recently USNRC-approved best-estimate LOCA methodology (BELOCA) was applied to perform the AP600 standard safety analysis report large-break LOCA analysis. The applicability of the WCOBRA/TRAC code to model the AP600 unique features was validated against CCTF and UFTE downcomer injection tests, the blowdown and reflood cooling heat transfer uncertainties were re-assessed for the AP600 large-break LOCA conditions, and a conservative minimum film boiling temperature was applied as a bounded parameter for blowdown cooling. The BELOCA methodology was simplified to quantify the code uncertainties due to local and global models as well as the statistical approximation methods, with the other uncertainties being bounded by limiting assumptions on the initial and boundary conditions. The final 95 percentile peak cladding temperature (PCT95%) was 1186 K, which meets the 10CFR50.46 criteria with a considerable margin. It is therefore concluded that the AP600 design is effective in mitigation of a postulated large-break LOCA.
Simulation of Some Emergency Operating Procedure for VVER-440 Reactors
Authors: Bánáti József , Ézsöl György 
Published: March 2022

Abstract
During the last few years the safety of the Hungarian Paks Nuclear Power Plant was reassessed in the framework of the AGNES project. Results of the program revealed that the safety of VVER-440/213 type reactors could be enhanced by modernizing a number of event oriented emergency operating procedures (EOPs) and the implementation of accident management (AM). Before the accomplishment of systematic AM all the possible thermal-hydraulic effects and consequences should be considered and experimentally verified.
This paper summarizes the most important findings of the relevant tests performed in the PMK-2 facility, which is a full-pressure, integral-type model of the Paks NPP. The present analysis concentrates on a particular method, the bleed-and-feed, applied in the primary or secondary circuit and conclusions are drawn for the effectiveness of this AM measure. Modelling of the thermal-hydraulic processes is extended with computer simulations using the RELAP5/MOD3.2 system code. Finally, a short assessment is given for the code capabilities to represent some significant phenomena of the transients.
Computational Fluid Dynamics Analysis of Thermal Mixing in the AP600 Upper Head
Authors: Schwirian R. E. 
Published: March 2022

Abstract
The paper discusses studies conducted to determine the extent of thermal mixing in the upper head region of the AP600 pressurized water reactor (PWR). This information is ultimately useful in the assessment of thermally-induced stresses in the upper head itself and the components adjacent to it. Coolant temperature profiles in the upper head region are also of interest in the evaluation of transients in which buoyancy forces are significant, such as natural circulation (NC) cooldown.
Scaling Analysis of AP600 Long Term Cooling Performance
Authors: Ortiz Marcos G. , Nielson Constance E. , Teerlink Laura 
Published: March 2022

Abstract
Westinghouse’s AP600 thermohydraulic design, with passive safety features, poses new challenges to computer simulation and analyses, the design of experimental test facilities to represent it, and to the proper interpretation of the data from these facilities. The conventional approach of modeling the reactor thermohydraulic system as a closed, steady state, natural circulation loop from which non-dimensional groups of parameters can be derived and used in the design of integral tests, is limited and can not capture the abrupt time-varying open system nature of the new design.
A rigorous and systematic, eight-step methodology has been developed to scale and interpret the results from three different integral test facilities, and to relate them to the full scale plant. In this paper, the aforementioned scaling methodology is applied to the analysis of the long term cooling phase of the AP600 behavior. This long term cooling phase, which appears independent of the initiating event, is divided for its analysis into two sub-phases. A first sub-phase dominated by the draining of the large In-Containment Refueling Water Storage Tank through the primary systems, and a second sub-phase characterized by the quasi-steady recirculation of coolant through the reactor vessel and the outside of the primary system. The analysis shows that with a few verifiable assumptions one can determine the key parameters and non-dimensional groups that govern the behavior in either of these sub-phases. One then uses these parameters and non-dimensional groups to evaluate the relevancy of existing test data.
The Influence of Processing on Structural Behaviour: An Interface Between Moldflow and ABAQUS
Authors: Bruijs Wim , Brounné Rob 
Published: March 2022

Abstract
It is well known that the injection molding process has an influence on the structural behaviour of the final plastic part. Due to shrinkage- and warpage effects, the final part does not have the same geometry as the mold, and it contains stresses. Nowadays cost and weight restrictions force part designers to use materials up to their mechanical limits. This puts very stringent requirements on the computer aided engineering of the parts and it becomes more and more important to account for the influence of the injection molding process on the part performance.
Moldflow is a versatile processing simulation program which, among others, is capable of predicting the warped shape and the molded-in stresses in a part. ABAQUS is a general purpose structural finite element program that is used to predict the behaviour of the part under a specific load. This paper describes an interface between the two programs which transforms the warped shape and the internal stresses as calculated by Moldflow to ABAQUS. A structural analysis can be performed based on the warped shape and taking into account the stresses.
The interface has been used to predict the shape of an injection molded thermoplastic fender. For this application, tight gap and flush requirements put strict requirements on the shape of the fender after mounting it on the vehicle. To be able to judge this shape, a special measurement method has been developed by RENAULT. In this method the plastic fender is placed on a measurement jig and fixed in a prescribed order. Afterwards the fender is measured and based on the results of these measurements the shape of the fender can be judged.
This procedure is simulated using the interface and taking into account warpage and molded-in stresses. For reasons of comparison, this simulation is also done without taking into account the molded-in stresses. The results of both simulations are compared with actual test data supplied by RENAULT and it can be concluded that accounting for the actual warpage results in a more accurate prediction of the fender shape.
The use of the interface can help in finding the optimal fender shape and the best molding conditions at a stage in the design phase where the final fixing system is not yet decided and tools still have to be made. In this way it helps to shorten the design cycle considerably.
An Optimization Scheme for Part Quality in Injection Molding
Authors: Ye Hua , Wu YingHui , Wang K. K. 
Published: March 2022

Abstract
In this paper, a mathematical definition of part warpage is presented by strain tensors and part quality is quantified via numerical simulation. An objective function of part quality is proposed that must be optimized. The resulting optimum is obtained by iterative search in the constrained space based on an numerical optimization algorithm — Simulated Annealing method, which is a global and robust method. The efficiency of the simulated Annealing method is in between calculus-based methods, such as DFP, BFGS, MFD and common search schemes, such as, simplex and exhaust search method, etc. (Goffe, 1994). The results are shown by a number of numerical examples where the part warpage is significantly reduced after optimization.
Prototype Design and Process Optimization Procedure for Products From Glass-Fiber Reinforced Polymer Blends
Authors: Narh K. A. , Xanthos M. 
Published: March 2022

Abstract
In order to minimize the effects of compositional variation in multiphase, multicomponent polymer mixtures equivalent to those found in commingled waste streams, such as those obtained from reclamation/recycling operations of post-consumer containers, several plastic composites containing varying amounts of glass fiber and different compatibilizers/coupling agents are studied. The glass-fiber reinforced composites, based on characteristic compositions simulating post-consumer “curbside tailings”, have been designed and molded into thin-section parts. Structural, and flow analyses were performed with commercial software on different types of plastic parts. Most of the data used in the simulation were experimentally generated on the compatibilized HDPE based polymer blends containing 20% short glass fibers. Issues concerned with injection molding and product performance are discussed.
Sensor/Model Fusion for Improved Process Understanding and Control in Injection Molding
Authors: Chien Li-Jen , Thomas Charles L. , Lawson Del R. 
Published: March 2022

Abstract
Many types of sensors have been investigated to monitor the process conditions in an injection mold during the molding process. Sensors such as thermocouples, pressure sensors, optical sensors, and ultrasonic sensors have been used to monitor the material, mold, and machine status during molding. Users have always found disadvantages or constrains in application for each type of sensor. Certain sensors can only be applied below a certain temperature. They may be hard to install at a critical location, or have difficulty in making an on-line measurement. A model of the process can predict molding conditions and polymer behavior at any location in the process, but the result is not on-line and the accuracy may be unacceptable. In this work, the signals from a cavity pressure sensor and an ultrasonic sensor are used in conjunction with a finite difference model to predict conditions in an injection mold during molding. The combination improves the model predictions and allows monitoring of variables that are not easily measured. Using this system one sensor is used to provide feed back to improve the model accuracy, while the model acts as a “virtual sensor” predicting the output of a variable that is not as easily measured.
New Ultrasonic Solidification Sensing Techniques for Injection Molding
Authors: Jiang Mingwen , Thomas Charles L. , Peterson Rob , Bur Anthony J. 
Published: March 2022

Abstract
An ultrasonic transducer installed facing a pressure transducer in the cavity of a rectangular plaque injection mold shows new sensitivities to the solidification of the polymer in the mold. Features of the amplitude variation of a pulse transmitted twice through the polymer are sensitive to the flow rate and solidification state of the polymer at the transducer face. The signal from a normal incidence shear transducer gives a direct indication of solidification. A model was developed to describe the changing amplitude of a pulse transmitted through the polymer. The model illustrates how temperature, pressure, flow rate, and signal frequency affect the measured echo amplitude.
Modeling Race Tracking Effects in Liquid Composite Molding
Authors: Chan Albert W. , Morgan Roger J. 
Published: March 2022

Abstract
Fabrication of polymer composite components for automotive applications typically involve the injection of a reactive polymer resin into a preform placed in a closed mold. This process, generally referred to as liquid composite molding, offers the opportunity for part consolidation and fabrication of large, complex shaped parts in a single molding step. A problem often encountered in the molding of composite components is the channeling flow (or race tracking) of resin along the periphery of the preform. This race tracking flow occurs as a result of a small clearance between the preform periphery and the mold. The resistance to flow in the peripheral clearance is much smaller than that in the bulk preform; hence, resin preferentially flows through this region.
This paper will present an integrated approach to modeling flow (both in the preform and along the periphery) in the mold cavity. The objective is to model race tracking as part of the overall flow problem. The solution essentially involves the interfacing of the two flow domains along the preform periphery. An integrated approach will not only lead to more accurate model predictions, but will also lead to improved computational efficiency. Example case studies will be presented to illustrate the importance of including race tracking in modeling liquid composite molding operations.
Green’s Function Approach to the Analysis of Functionally Graded Materials
Authors: Nomura Seiichi , Sheahen Donna M. 
Published: March 2022

Abstract
A micromechanical approach is adopted to systematically obtain numerical Green’s function for functionally graded materials (FGMs) which enables expressing thermomechanical fields in FGMs as a convolution type of integrals between the Green’s function and a source function. The numerical Green’s function is sought by the eigenfunction expansion method. Computer algebra systems are essential to derive admissible functions that satisfy the given boundary conditions and manipulation of the algebra involved. Using the Green’s function for FGMs, physical fields in FGMs can be expressed semi-analytically while retaining all the relevant parameters. In addition, any change in boundary conditions such as temperature can be readily reflected without incurring the entire recalculation.
Crack Tip Stress Fields and Creep Crack Growth of Interface Cracks in Functionally Graded/Layered Materials
Authors: Biner S. B. 
Published: March 2022

Abstract
In this study, the growth behavior of interface cracks in bimaterials and in graded/layered materials resulting from the creep cavitation was studied. The growth model includes the effects of material deposition resulting from the growth of creep cavities on the crack tip stress fields. The results indicate that in graded/layered materials under identical applied loading, the location of the interface crack strongly influence the amplitude of the stress field (C*) at steady-state. Due to large variation in the distribution of the stresses ahead of the interface cracks at creep regime, depending upon the crack location, the creep crack growth rates will be significantly different from each other under identical loading for a given graded/layered material.