Developed Test Rig Research Articles

English

This paper is a portion of research carried out for the industrial and evaluation of riot police helmet having constant textile reinforcement. Successful procedure was developed for the manufacturing on single-piece constantly textile reinforced riot helmet shells. In order to fulfil the impartial of in-house impact testing on the developed continuously textile reinforced helmets, a helmet test rig was made. The Academy of Manchester's drop weight impact testing device was used and successfully changed for helmet testing.The importance of the developed test rig was the adequate abilities to carry out impact testing at dissimilar impact position at the helmet shell, force blocking effectiveness at diverse locations can be designed and the behavior of the communicated force at dissimilar impact locations can be understood. Furthermore, energy absorption at different impact location can also be studied. Keywords-Helmet, Continuous Textile Reinforcement, Impact Testing, Test Rig, Drop Weight Impact Testing Instrument.

Effect of strain rate on bending and transmission characteristics of injection molded polyamide 66 spur gears

Polymer material exhibits time-dependent mechanical behavior due to its viscoelastic characteristics. Thus, unlike steel gears, polymer gears exhibit complex behavior when transmitting loads at various rotational speeds. In general, gear tooth surfaces exhibit complex stress due to their nonconformal geometry. Hence, the nonlinear material and nonlinear geometric aspects of polymer gear mesh prompted an investigation of the bending and transmission characteristics of injection molded polyamide 66 gears at various strain rate conditions. The injection molded tensile specimens made from the gear material were subjected to various rates of loading. The stress–strain performance at various rates of loading was evaluated and used to model linear and nonlinear gear materials for the numerical analysis. The numerical investigation was carried out on the steel–polyamide gear pair with the commercial finite element analysis tool ABAQUS® to predict the bending stress and static transmission error. The predicted static transmission error of the gear pair was compared with the experimental results obtained using an in-house developed gear test rig. The bending stress with the linear material models was higher than that of the nonlinear material models. An increase in bending stress with the strain rate was observed in the case of the nonlinear material models. The static transmission error predicted with the nonlinear material model at a higher strain rate was lower for both the single tooth contact and the double teeth contacts.

Large scale detonation testing: New findings in the prediction of DDTs at large scales

A large vapor cloud explosion (VCE) followed by a fire is one of the most dangerous and high-consequence events that can occur at petrochemical facilities. As the size and complexity of facilities increase, designs must consider the potential adverse effects associated with vapor cloud explosions in large congested areas and understand the potential for more devastating deflagration-to-detonation transitions (DDTs) on these facilities. While the likelihood of DDTs is lower than deflagrations, they have been identified in some of the most recent large-scale explosion incidents including: 2005 Buncefield explosion, 2009 San Juan explosion, and 2009 Jaipur event. The consequences of DDTs can be orders of magnitude larger than deflagration because they have the ability to self-propagate outside the region of high congestion/confinement. Hence, it is critical to understand how a facility's geometry or equipment layout can affect explosion consequences and assist in their mitigation and/or prevention.Due to the inability to predict such devastating phenomena on the large scale, owners and designers cannot evaluate installations for risk of DDTs and provide “inherently safer” layout or mitigation measures to significantly reduce or eliminate such hazards. However, there is a lack of data at the large scale to validate the necessary design tools used to predict the risk of DDT. One of the main goals of this research project is to provide large scale DDT explosion data and validate the tools necessary to predict vapor cloud explosions in early design phase.This paper will present the results of large scale testing being conducted in a newly developed test rig of 50,000 ft3 (1500 m3) gross volume under award Subcontract 12121-6403-01 provided by the Research Partnership to Secure Energy for America (RPSEA). These tests involve evaluation of deflagrations and DDTs involving stoichiometric, lean and rich mixtures, with propane and methane fuels. The effectiveness of mitigation techniques such as solid inhibitors or deluge is evaluated for preventing DDTs.

Development of paddy stripper header mechanism

Stripping is the process of removing the seeds from the plant and straw remained anchored to the soil. The main advantages of stripping is the increasing capacity of the combine harvester with reduced amount of material other than grain ratio (MOG) and power requirement for threshing and cleaning which promotes to develop small and light weight mechanism suitable for small and fragmented land. A laboratory stripper header mechanism (SHM) was developed for stripping paddy grains and collecting them in grain tank. It consisted of stripping rotor, stripping elements, hood, frame and grain tank. Two profiles of stripping elements viz., slender arrow head (A) and spaced slender arrow head (B) of stripping elements were used. The performance of the developed SHM was evaluated on specially developed test rig to study the effect of two levels of forward speed (1.65 and 2.25 km/h) and four levels of peripheral speed (16.95, 19.78, 22.6 and 25.45 m/s) on shattered and un-stripped grain loss was studied. It consisted of track, platform and crop holders. SHM was stationary and platform was movable on track. Minimum shattered grain loss of 5.78 per cent was obtained with stripping element A at 2.25 km/h forward speed and at 19.78 m/s peripheral speed. Minimum un-stripped grain loss of 0.84 per cent was obtained with stripping element A at 2.25 km/h forward speed and 25.45 m/s peripheral speed. The performance of the slender arrow head stripping element was found to be better as compared to spaced slender arrow head.

A prototype telerobotic platform for live transmission line maintenance: Review of design and development

This paper reports technical design of a novel experimental test facility, using haptic-enabled teleoperation of robotic manipulators, for live transmission line maintenance. The goal is to study and develop appropriate techniques in repair overhead power transmission lines by allowing linemen to wirelessly guide a remote manipulator, installed on a crane bucket, to execute dexterous maintenance tasks, such as twisting a tie wire around a cable. Challenges and solutions for developing such a system are outlined. The test facility consists of a PHANToM Desktop haptic device (master site), an industrial hydraulic manipulator (slave site) mounted atop a Stewart platform, and a wireless communication channel connecting the master and slave sites. The teleoperated system is tested under different force feedback schemes, while the base is excited and the communication channel is delayed and/or lossy to emulate realistic network behaviors. The force feedback schemes are: virtual fixture, augmentation force and augmented virtual fixture. Performance of each scheme is evaluated under three measures: task completion time, number of failed trials and displacement of the slave manipulator end-effector. The developed test rig has been shown to be successful in performing haptic-enabled teleoperation for live-line maintenance in a laboratory setting. The authors aim at establishing a benchmark test facility for objective evaluation of ideas and concepts in the teleoperation of live-line maintenance tasks.

Temporal evolution of auto-ignition of ethylene and methane jets propagating into a turbulent hot air co-flow vitiated with NOx

In this paper, the temporal evolution of auto-ignition (AI) of C2H4 and CH4 jets propagating into a NOx vitiated hot co-flow at high velocity and turbulence was studied. Simultaneous temporally-resolved planar laser-induced fluorescence (PLIF) experiments of OH and CH2O were carried out in a recently developed test rig for auto-ignition studies of turbulent non-premixed flows. Flame stabilization mechanisms were analyzed for both fuels at several operating conditions. The reaction progress of AI kernels as well as their apparent growth rate were evaluated. Results revealed that the stabilization mechanism (i.e. lifted flame or isolated kernel) strongly depends on the turbulent mixing, co-flow temperature and fuel composition. A further statistical analysis of the heat release rate (HRR) zones, calculated as the product of the CH2O- and OH-PLIF signals, delivered an indication on the different AI characteristics of C2H4 and CH4. An evaluation of the temporal evolution of the HRR for C2H4 jets provided a deeper insight about the reaction progress at different conditions of the co-flow, when AI was initiated by isolated kernels. Finally, estimations of the apparent growth rate of AI kernels indicated a faster propagation of C2H4 kernels when compared with those of CH4.

Experimental investigations on regeneration energy and energy management strategy in series hydraulic/electric synergy system

ABSTRACTThis research work draws an insight into the experimental investigations on a series hydraulic/electric synergy system—a green transportation system. An experimental test rig of the system with all necessary sensors and instrumentation has been developed to study the energy saving through hydraulic regenerative braking. The effect of various system parameters, such as braking time, maximum accumulator pressure, pre-charge pressure of hydro-pneumatic accumulator, volumetric displacement of the hydraulic master pump, and hydraulic regeneration pump on the quantum of regeneration energy, was analyzed. In addition, an AMESim model of the real-time experimental test rig has been developed and validated with experimental results. A set of five different experimental designs (parameter variations) of the system is defined with the available standard component sizes. The best design is selected of the available experimental designs based on the maximum hydraulic regeneration energy and regeneration efficiency. It was observed that the selected design has an energy efficiency of 13.3% and a regeneration efficiency of 43.8%. An accumulator-centric control strategy for energy management is developed and implemented on the experimental test rig configured with the selected design. The effectiveness of the control strategy is tested through experiments and simulation on the developed test rig.

밸브트레인용 롤러태핏 하우징의 제작 공정 개발 및 시제품 평가

본 연구에서는 엔진의 밸브트레인에 적용되는 롤러 태핏 하우징의 냉간단조 공정을 개발하였다. 시제품을 제작하였으며, 태핏 하우징의 내구성 평가를 통하여 작동성을 확인하였다. 소재 시편의 압축시험을 통하여 태핏에 사용되는 소재의 물성을 확보하고 상용 소프트웨어인 Deform-3D을 이용하여 단조해석을 수행하였다. 해석결과를 바탕으로 냉간단조 공정을 설계하였으며, 실제 금형을 제작하고 시제품을 제작하였다. 제작한 시제품의 평가를 위하여 치수정밀도, 표면조도, 평행도, 동심도를 확인하였으며, 목표한 항목에 모두 부합하는 결과를 확인하였다. 또한 제품의 작동성 및 내구성 평가를 수행하기 위하여, 엔진 밸브트레인의 구동을 모사하는 별도의 시험장치 개발을 완료하였다. 디젤엔진의 아이들 상태를 가정하여 작동성을 평가하고, 엔진의 최고 회전수를 가정하여 내구성 시험을 진행하였다. 시험결과 태핏하우징의 마모는 시험 전, 후 외경 치수 0.002 mm 감소로, 미소한 마모를 보였다. 본 연구를 통하여 정밀 냉간단조 기술을 이용한 제품개발 프로세스를 정립하였다. 또한 본 연구에서 개발한 작동성 평가 시험기를 통해 밸브트레인용 부품의 작동성 및 내구성 평가 시험이 가능할 것으로 사료된다. In this study, a cold forging process was developed for the roller tappet housing of an engine valvetrain system. A tappet sample was manufactured and subjected to an endurance test. The material properties were obtained from a compression test, and forging analysis was carried out to design a forging process using a commercial program, Deform-3D. The forging process was set up based on the analysis results, and a die set and sample tappet housing were manufactured. To evaluate the sample, the dimensional accuracy, surface roughness, parallelism, and concentricity were measured and confirmed. To evaluate the actuation and durability, a special test rig was developed to simulate the valvetrain system of the engine. An actuation test was performed based on the idle speed of a general diesel engine, and an endurance test was done based on the maximum speed. The results show minor wear of 0.002 mm. The developed test rig will be used to evaluate the actuation and durability of other valvetrain parts.

A novel approach integrating dimensional analysis and neural networks for the detection of localized faults in roller bearings

Abstract The detection of the defective/worn out bearing components used in rotating machines is one of the main concerns in various applications. To improve the computational efficiency in the nonlinear dynamic analysis for the rolling contact bearings, a new methodology based on dimensional analysis (DA) theory is proposed in this paper. The developed model is used to predict the vibration responses due to artificially spalled bearing components to quantify the level of structural damages into these components. The use of a back propagation neural network (BPNN) has been made that also predicted responses from the network trained by developed algorithm using the experimental data obtained from the defective bearing components on the developed test rig. A comparison between the responses predicted by proposed DA method and the BPNN showed a fair amount of the agreement between the two approaches and validated the proposed model and proved outstanding tool for identification of spalled/damaged bearing components.

Force and Flow Field Measurement System for Tandem Flapping Wings

A test rig is developed to investigate the force and flow field characteristics of tandem flapping wings. The setup comprises a low Reynolds number recirculating water tunnel, two sets of plunge and pitch motion rigs, and a force and flow field acquisition system. A program for the motion and data acquisition is developed based on the NI LabVIEW platform. The water tunnel mainly consists of a water tank, a contraction section, a test section, and a centrifugal pump system. Many kinematic parameters of the tandem flapping motion can be adjusted in our developed test rig. These parameters are the phase angle between flapping motions of the forewing and hindwing, as well as the spacing distance, flapping frequency, and amplitude of the forewing and hindwing. The prominent feature of the motion rigs is that the phase angle can be adjusted continuously from 0 to 360°. The thrust and lift on the flapping wing are measured by a three-dimensional force sensor. A square wave produced by the program is used to identify the start of the flapping motion. The flow field around the flapping wing can be captured by a digital particle image velocimetry (DPIV) at the desired phases of the motion because the DPIV can be triggered by a square wave at any time within a cycle. The boundary of a vortex is determined according to the λ2-criterion with DPIV measurement data, and then its circulation can be computed.

Surface durability of injection-moulded carbon nanotube–polypropylene spur gears

Short fibre reinforced thermoplastics are being considered for light- and medium-duty engineering applications because of their improved mechanical strength combined with cost-effective advantages. In recent years, the carbon nanotube reinforced thermoplastics are being preferred over the short fibre reinforced thermoplastics because of the absence of directional shrinkage characteristics, directional mechanical and tribological properties. In this work, 1 wt% carbon nanotube–polypropylene material was injection-moulded to spur gears and evaluated for the durability using in-house developed power absorption gear test rig. During testing, the net surface temperature of the test gears and in-line torque available at the driver and driven shafts were continuously measured. The measured torque was used to evaluate the transmission efficiency of the test-steel gear pair. The measured net surface temperature was correlated with the gear failure mode. Test gears were run up to failure or up to 8.6 × 105 cycles, whichever occurred first. Worn-out gear tooth surfaces were observed using an optical and scanning electron microscope to understand the wear mechanism. In the initial stage of service, test gears exhibited less wear near the pitch region compared to the tip and root regions. This behaviour is due to the maximum sliding velocities at the tip and root regions compared to the pitch region. The carbon nanotube–polypropylene gears exhibited lower surface temperature (5−10 ℃), improved service life (30%−80%) and higher transmission efficiency (1−1.5%) compared to the polypropylene gear.

How to guide lubricants – Tailored laser surface patterns on stainless steel

In this experimental study, periodic line-like structures with different periodicities (5, 10, 19, and 300μm) and structural depths (approximately 1 and 4μm) were fabricated on stainless steel samples (AISI-304) by short-pulse laser interference and ultrashort-pulse laser patterning. A detailed characterization of the resulting surface topography was performed by white light interferometry and scanning electron microscopy. The spreading dynamics of additive-free synthetic polyalphaolefine oil on a polished reference sample are compared to laser patterned surfaces. These studies are conducted using a newly developed test rig, which allowed for controlled temperature gradients and a precise recording of the spreading dynamics of lubricants on sample surfaces. It could be demonstrated that the spreading velocity parallel to the surface pattern is higher for all samples which can be explained by increased capillary forces and liquid pinning induced by the surface patterning. Furthermore, a decline of the spreading velocity over time for all samples and orientations is clearly visible which can be traced back to a viscosity increase induced by the temperature gradient and a reduced droplet volume. For parallel orientation, the experimental findings are in good agreement with the Lucas–Washburn equation and established models.

Model Development for Investigation of Localized Defects in Taper Roller Bearings Using Matrix Method of Dimensional Analysis

Catastrophic failures of the rotating machineries can be avoided by tracing the faults generated in the rolling contact bearings used for supporting these machines and are important sources of noise, vibration as well as sudden stoppage of the entire production or interruption of processes. A generalized model is developed using Matrix Method of Dimensional Analysis (MMDA) to establish dimensionless correlation between the response and consequence parameters for the assessment of localized surface defects in the different components of taper roller bearings tested on a developed test rig. Response surface methodology (RSM) is employed for the experimentation and to explore the dependence of various factors on the vibrations of these bearings. A numerical analysis performed in the study showed the effectiveness of MMDA model along with frequency domain scrutiny of the vibration data for detection of localized bearing defects.

Wear behavior for striated ridge intersected with obtuse angle on a newly developed test rig

Experimental study of wear characteristics for striated ridge intersected by two surfaces with obtuse angle were carried out with a newly developed test rig, with the purpose of gaining insight into its wear resistance. The developed test rig was a rotational one with axes supported on a lathe, which enabled geometrical alterations of wear pair with system load flexibility and online monitoring. The full-scale and orthogonal experiments for striated ridge wear were conducted for sensitivity analysis and obtaining optimal parameters combination for minimum wear, respectively. In addition, surface morphology was checked by optical inspection and mechanical behavior was studied utilizing finite element method. The results show that the wear resistance of striated ridge was better than that of the smooth ridge. The striated ridge had better wear resistance with greater striation area ratio. The order of the factors’ impact on ridge wear depth loss was: surface intersecting angle, striation quantity and striation width. Furthermore, the striate units across the ridge can lower the von Mises stress and shear stress on the ridge and relax the stress distribution of materials, leading a decrease of the ridge wear.

S1120101 超小型不思議遊星歯車減速機の耐久性に関する研究

This paper studies a durability of a ultra-micro reduction gear using the mechanical paradox planetary gear mechanism. The module of the gears are 0.1 and the diameter of the unit is 10.6 mm. The gears are made of fiber reinforced PPS (poly phenylene sulfide). Durability tests were carried out using a developed test rig. The wear amount was evaluated using the base tangent length measured by a profile projector. Backlash of the unit was also evaluated. The based tangent length decreased slightly (1% in maximum) in the durability test. The median of the backlash increased slightly (0.1 degrees) after the durability test. Some large backlash values, which are larger than 0.5 degrees, were observed after the durability tests.

An Experimental Study on Dynamics of a Novel Dual-Belt Continuous Variable Transmission Based on a Newly Developed Test Rig

A novel dual-belt Van Doorne’s continuous variable transmission (DBVCVT) system, which is applicable to heavy-duty vehicles, has been previously proposed by the authors in order to improve the low torque capacity of traditional single-belt CVT. This DBVCVT is a novel design among continuously variable transmissions and is necessary to be prototyped for experimental study, and the analytical dynamic model for this DBVCVT also needs to be experimentally validated. So, this work originally fabricated a prototype of DBVCVT and integrates this prototype to a light-load hardware-in-the-loop test rig by replacing the engine and load equipment with the AC motor and magnetic powder dynamometer. Moreover, with the use of this newly developed test rig, this work implements the experimental study of this DBVCVT for the first time. The comparison of experimental and simulation results validates the previously proposed analytical model for DBVCVT, and some basic characteristics of the DBVCVT in terms of the reliability, speed ratio, and transmission efficiency are also experimentally studied. In all, this developed test rig with the analytical model lays the foundation for further study on this novel DBVCVT.

Experimental study of hydrodynamic pressure distribution in oil lubricated two-axial groove journal bearing

Hydrodynamic pressures in oil lubricated two-axial groove finite journal bearing is measured experimentally using a newly developed test rig. Details of design and fabrication of the test rig is presented. Hydrodynamic oil film pressures were measured using two techniques, viz. pressure measurement with sensor mounted on shaft surface and pressure measurement with sensor located outside the bearing assembly. Pressure measurement with first approach was found to yield only the groove pressures. The maximum pressures obtained using second approach is compared with theoretical values. Maximum experimental pressures are found to have a 20% difference in comparison with theoretical maximum pressures.

A direct experimental–numerical method for investigations of a laboratory under-platform damper behavior

Under-platform dampers are commonly adopted in order to mitigate resonant vibration of turbine blades. The need for reliable models for the design of under-platform dampers has led to a considerable amount of technical literature on under-platform damper modeling in the last three decades.Although much effort has been devoted to the under-platform damper modeling in order to avail of a predictive tool for new damper designs, experimental validation of the modeling is still necessary. This is due to the complexity caused by the interaction of the contacts at the two damper-platform interfaces with the additional complication of the variablity of physical contact parameters (in particularly friction) and their nonlinearity. The traditional experimental configuration for evaluating under-platform damper behavior is measuring the blade tip response by incorporating the damper between two adjacent blades (representing a cyclic segment of the bladed disk) under controlled excitation. The effectiveness of the damper is revealed by the difference in blade tip response depending on whether the damper is applied or not. With this approach one cannot investigate the damper behavior directly and no measurements of the contact parameters can be undertake. Consequently, tentative values for the contact parameters are assigned from previous experience and then case-by-case finely tuned until the numerical predictions are consistent with the experimental evidence. In this method the physical determination of the contact parameters is obtained using test rigs designed to produce single contact tests which simulate the local damper-platfom contact geometry. However, the significant limitation of single contact test results is that they do not reveal the dependence of contact parameters on the real damper contact conditions. The method proposed in this paper overcomes this problem.In this new approach a purposely developed test rig allows the in-plane forces transferred through the damper between the two simulated platforms to be measured, while at the same time monitoring in-plane relative displacements of the platforms. The in-plane damper kinematics are reconstructed from the experimental data using the contact constraints and two damper motion measurements, one translational and one rotational. The measurement procedures provide reliable results, which allow very fine details of contact kinematics to be revealed. It is demonstrated that the highly satisfactory performance of the test rig and the related procedures allows fine tuning of the contact parameters (local friction coefficients and contact stiffness), which can be safely fed into a direct time integration numerical model.The numerical model is, in turn, cross-checked against the experimental results, and then used to acquire deeper understanding of the damper behavior (e.g. contact state, slipping and sticking displacement at all contact points), giving an insight into those features which the measurements alone are not capable of producing. The numerical model of the system is based on one key assumption: the contact model does not take into account the microslip effect that exists in the experiments.Although there is room for improvement of both experimental configuration and numerical modeling, which future work will consider, the results obtained with this approach demonstrate that the optimization of dampers can be less a matter of trial and error development and more a matter of knowledge of damper dynamics.

Development of a novel miniature high-pressure fuel pump with a low specific speed

Whenever a small amount of fluid has to be pumped against a high differential pressure, various types of piston pumps are typically used. However, the need for excellent suction behaviour, for the possibility of a dry run and for minimal manufacturing costs requires the development of alternative pump concepts. This paper presents the development of a novel miniature high-pressure fuel gear pump to replace the feed pump as well as the high-pressure pump in gasoline direct-injection fuel systems. It was found that the clearance between the housing and the rotating gears has to be reduced to a minimum in order to keep the internal leakage at a reasonable level. Based on theoretical predictions a radially and axially pressure-compensated pump concept was developed by incorporation of a floating sealing element able to minimize the tip and face leakages. The design of this sealing element was optimized in the course of experimental investigations. The experiments were carried out using a specifically developed test rig, and the obtained results prove that the optimized pump is able to generate the required differential pressure Δ p = 40–50 bar at a specific speed nq = 0.005–0.400 r/min. The measured Δ p–Q curves were almost vertical beyond a certain pressure level, yielding a nearly pressure-independent volumetric efficiency of approximately 75%. The developed pump concept finally offers outstanding performance characteristics in an operation range where conventional gear pump concepts usually lose importance owing to unacceptably high volumetric losses.

Experimental measurement and modelling of plain bearing wear in start–stop applications

The implementation of CO2 saving technologies such as start–stop has introduced new constraints on the engine bearings and their operating environment. The number of expected start–stops of a modern hybrid engine has risen to about 1.2 million for the engine lifetime. Frequent operation under mixed and boundary lubrication regimes may noticeably increase wear and reduce the life of the bearings. The developed test rig and modelling software are capable of simulating engine transient working conditions. The test results confirmed higher wear resistance of a bearing with a polymeric overlay working under start–stop conditions in comparison to an aluminium bimetallic bearing. Simulation results calculated on the basis of the ‘Direct Contact Reaction’ and correlated with the experimental data made it possible to estimate the wear of the bearings working in different start–stop applications.