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Viewing 1 to 30 of 305
2017-06-05
Technical Paper
2017-01-1908
Rong Guo, Jun Gao, Xiao-kang Wei, Zhao-ming Wu, Shao-kang Zhang
This work aims to provide theoretical basis for improving engine shake performance based on full vehicle model by optimizing the design parameters of hydraulic engine mounts (HEMs). The definition of the engine shake problem is presented through comparing the quarter vehicle models with the rigid-connected and flexible-connected powertrain which is supported by a rubber mount. Then the model is extended by replacing the rubber mount as a HEM with regard to the inertia and resistance of the fluid within the inertia track. Based on these, a full vehicle model with 14 degree of freedoms (DOFs) is proposed to calculate the engine shake, which consists of 6 of the powertrain, 1 of the fluid within the inertia track of the HEM, 3 of the car body and 4 of the unsprung mass. Parameter study is performed to determine the most effective parameters of the HEM influencing engine shake and then the HEM is optimized through the genetic algorithm (GA).
2017-06-05
Technical Paper
2017-01-1826
Sagar Deshmukh, Sandip Hazra
Engine mounting system maintains the position of power train in the vehicle with respect to chassis and other accessories during inertia, torque reaction loads and roadway disturbances. The mounting system also plays a role in terms of isolation of the rest of the vehicle and its occupants from power train and helps in maintaining vehicle ride and handling condition. This paper investigates the performance comparison between a conventional mount, hydromount and switchable hydromount during idle condition and ride performance. The optimization scheme aims to improve the performance of the mounting system in order to achieve overall power train performance and NVH attribute balancing through semi active technology. Keywords: Engine Mount, NVH,Switchable Hydromount
2017-06-05
Technical Paper
2017-01-1822
Kopal agarwal, Sandip Hazra
Vehicle Drive away shudder is a vibration felt by customers at the time of marching off. The vibration is significantly felt at the time of Clutch Engagement as a shiver in vehicle. While the known reason of Shudder is clutch friction & engagement, in this study we have provided a solution to reduce the shudder by optimizing the power train mounting system. The shake occurs at approximately 10-20kmph in a medium sized car. The design of powertrain mounting system has been modified to achieve the reduction in shake. The pros & cons of the said change in mounting system on the overall NVH performance is also discussed.
2017-06-05
Technical Paper
2017-01-1907
Yang Wang, Yong Xu, Xiao Tan
OPTIMIZATION OF THE POWERTRAIN MOUNTING SYSTEM VIA DOE METHOD Authors: Wang Yang*, Wang Hui*, Xu Yong* * NVH Section, Brilliance-Auto Engineering Research Institute, Shenyang, China, 110141 Key Words: NVH; DOE; Powertrain Mounting System; Analysis of Variance Research and/or Engineering Questions/Objective The vibration isolation performance of vehicle powertrain mounting system is mostly determined by the three-directional stiffnesses of each mount block. Because of the manufacturing tolerance and the coupling effect, the stiffnesses of mounts cannot be maintained stable. The purpose of this study was to find out the way to optimize the stiffnesses of mounts via the design of experiments (DOE). Methodology According to the DOE process, a full factorial design was implemented. The z-direction stiffnesses of three mount blocks in the mounting system were selected as the three analysis factors.
2017-06-05
Technical Paper
2017-01-1829
Guillaume Loussert
The new fuel efficiency and emission standards have forced OEMs to put emphasis on different strategies such as engine downsizing, cylinder deactivation... Unfortunately these new technologies may lead to increased powertrain vibrations generated by the engine and transmitted to the chassis and the car cabin, such that their reduction or elimination has become a key topic for the automotive industry. The use of active engine mounts, acting directly on the fluid of an hydromount, or active vibration dampers, acting as an inertial mass-spring system, are very effective solutions, particularly when using electromagnetic based actuators. Nevertheless, all electromagnetic actuators technologies are not equals and the choice of such actuators must be considered carefully by taking into account the full performances and the overall cost of the solutions. This paper presents an electromagnetic actuator technology, that can be considered as the best tradeoff between performances and cost.
2017-04-11
Journal Article
2017-01-9175
Yitao Zhu, Makarand Datar, Kalyan Addepalli, Natalie Remisoski
Nowadays, the vehicle design is highly ruled by the increasing customer demands and expectations. In addition to ride comfort and vehicle handling, the Noise, Vibration and Harshness (NVH) behavior of the powertrain is also a critical factor that has a big impact on the customer experience. To evaluate the powertrain NVH characteristics, the NVH error states should be studied. A typical NVH event could be decoupled into 3 parts: source, path, and receiver. Take-off shudder, which evaluates the NVH severity level during vehicle take-off, is one of the most important NVH error states. The main sources of Front Wheel Drive (FWD) take-off shudder are the plunging Constant Velocity Joints (CVJ) on the left and right half shafts. This is because a plunging CVJ generates a third order plunging force with half shaft Revolution Per Minute (RPM), which is along the slip of the plunging CVJ.
2017-03-28
Technical Paper
2017-01-1059
Rong Guo, Jun Gao, Xiao-kang Wei
Abstract The active engine mount (AEM) is developed in automotive industry to improve overall NVH performance. The AEM is designed to reduce major-order signals of engine vibration over a broad frequency range, therefore it is of vital importance to extract major-order signals from vibration before the actuator of the AEM works. This work focuses on a method of real-time extraction of the major-order acceleration signals at the passive side of the AEM. Firstly, the transient engine speed is tracked and calculated, from which the FFT method with a constant sampling rate is used to identify the time-related frequencies as the fundamental frequencies. Then the major-order signals in frequency domain are computed according to the certain multiple relation of the fundamental frequencies. After that, the major-order signals can be reconstructed in time domain, which are proved accurate through offline simulation, compared with the given signals.
2017-03-28
Technical Paper
2017-01-1314
Santhoji Katare, Dilip Reddy, Amar Ourchane, Giri Nammalwar
Abstract Virtual Verification (VV) of engineering designs is a critical enabler in the Product Development (PD) process to reduce the time-to-market in a cost efficient manner. Reliance on cost effective VV methods have significantly increased with increased pressure to meet customer expectations for new products at reduced PD budgets. Computer Aided Engineering (CAE) is one such VV method that affords an engineer to make decisions about the ability of the designs to meet the design criteria even before a prototype is built. The first step of the CAE process is meshing which is a time consuming, manual and laborious process. Also mesh development time and accuracy significantly varies with the (1) component (trim body, engine, suspension, brakes, etc.), (2) features predominantly occurring in the component (welds, ribs, fillets, etc.), meshing guidelines based on which the model needs to be developed (durability, safety, NVH, etc.), and the expertise of the meshing engineer involved.
2017-03-28
Technical Paper
2017-01-0405
Tianqi Lv, Xingxing Feng, Peijun Xu, Yunqing Zhang
Abstract Three constitutive models which capture the amplitude and frequency dependency of filled elastomers are implemented for the conventional engine mounts of automotive powertrain mounting system (PMS). Firstly, a multibody dynamic model of a light duty truck is proposed, which includes 6 degrees of freedom (DOFs) for the PMS. Secondly, Three constitutive models for filled elastomers are implemented for the engine mounts of the PMS, including: (1) Model 1: Kelvin-Voigt model; (2) Model 2: Fractional derivative Kelvin-Voigt model combined with Berg’s friction; (3) Model 3: Generalized elastic viscoelastic elastoplastic model. The nonlinear behaviors of dynamic stiffness and damping of the mounts are investigated. Thirdly, simulations of engine vibration dynamics are presented and compared with these models and the differences between common Kelvin-Voigt model and other constitutive models are observed and analyzed.
2017-03-28
Technical Paper
2017-01-1056
Rong Guo, Xiao-Kang Wei, Jun Gao
Abstract Manufacturers have been encouraged to accommodate advanced downsizing technologies such as the Variable Displacement Engine (VDE) to satisfy commercial demands of comfort and stringent fuel economy. Particularly, Active control engine mounts (ACMs) notably contribute to ensuring superior effectiveness in vibration attenuation. This paper incorporates a PID controller into the active control engine mount system to attenuate the transmitted force to the body. Furthermore, integrated time absolute error (ITAE) of the transmitted force is introduced to serve as the control goal for searching better PID parameters. Then the particle swarm optimization (PSO) algorithm is adopted for the first time to optimize the PID parameters in the ACM system. Simulation results are presented for searching optimal PID parameters. In the end, experimental validation is conducted to verify the optimized PID controller.
2017-03-28
Journal Article
2017-01-0420
Prashant Khapane, Sumiran Lohani
Abstract Vibration Isolation is the key objective of engine mounting systems in the automotive industry. A well-designed, robust engine mount must be capable of isolating the engine assembly from road-based excitations. Owing to high vibration inputs, engine mounts are susceptible to wear and failure. Thus, the durability of engine mounts is a cause for concern. A design validation methodology has been developed at Jaguar Land Rover using Multibody Dynamics (MBD) to enhance the prognosis of engine mount loads during full - vehicle durability test events. This paper describes the development of a virtual multi-axial simulation table rig (MAST Rig) to test virtual engine mount designs. For the particular example considered in this paper, a simple sinusoidal input is applied to the MAST Rig. The development of the virtual MAST Rig has been described including details of the modelling methodology.
2017-01-10
Technical Paper
2017-26-0287
Srinivas Kurna, Rahul Jain, Arpit Mathur, Mahendra Parwal, Adithya Legala
Abstract The Mounting system of component plays a major role in determining the structural durability, compatibility and synchronization of the systems with respect to each other. The major function of Engine mounts is to isolate the engine from the chassis and to align the power-train system of vehicle according to needs. Here we exclusively deal with the failure case of a Heavy duty commercial vehicle Engine Mounts and its optimization. We do formulate a theoretical calculation for the estimation of engine loads, Center of Gravity (C.G) and characteristics of existing engine mount followed by a failure root cause analysis based on design and transmissibility parameters. This is then correlated with data from Computed Aided Engineering and Matlab for analysis of the existing model which is compared to the experimental transmissibility from Road load data Acquisition (RLDA). This is to validate the conditions and propose optimizations to reduce critical failures.
2017-01-10
Technical Paper
2017-26-0196
Kopal Agarwal, Sandip Hazra, Vikas Kolage
Abstract Key on/off Vibrations plays an important role in the quality of NVH on a vehicle. Hence having a good KOKO in the vehicle is desirable by every OEM. The vibration transfer to the vehicle can be refined by either reducing the source vibrations or improving isolation. In this study, critical factors affecting KOKO vibration has been identified. Focus has been given on improving the KOKO by change in mounting system stiffness & stopper gap, and assuming other parameters as constant. The study highlights a new simulation approach using ADAMS View to help run a DOE for solving KOKO issue on vehicle. The contribution of C mount stiffness and stopper gap is shown through simulation results. The correlation between simulation & test results has been established by measuring rigid body modes and KOKO vibration on vehicle for a set of mount configuration. Test results show significant KOKO improvement with the mount configuration optimized through simulation.
2016-11-08
Technical Paper
2016-32-0042
Bhaarath Rajagopal Jeyapaal, Vamsi Krishna, Kannan Marudachalam
Abstract Vibrations have become an increasingly important attribute for determining the quality of automotive products. Particularly, this becomes more acute in the case of tactile vibrations of powered two-wheelers - motorcycles and scooters. This paper deals with vibrations of a scooter vehicle. Scooters are normally a two-wheeler with a four stroke single cylinder spark ignited engine. Vibrations of a scooter are mainly caused by the inertial imbalance forces of the engine, combustion forces and road undulations. Vibrations due to road undulations are mostly reduced by toggle link mechanism, resilient mounts of the engine and the shock absorbing suspension of the frame. The power train assembly is designed in such a way that the inertial imbalance forces in the power train assembly are distributed at a required angle called the ellipse angle.
2016-10-25
Technical Paper
2016-36-0149
Edinilson Alves Costa
Abstract Mainly in the last 30 years so much research has been done on Fe-based calculation of seam welded thin-sheet structures fatigue life. However, available prediction methods have been developed for a limited range of geometries under ideal load conditions. Extrapolating to complex real world geometries and load conditions such those resultant from, for example, ground vehicles dislocation over rough surfaces, are least documented. One example of the application of seam welded thin-sheet structures in the ground vehicle industry is the powertrain installation bracketry. Such brackets are subject to variable amplitude loading sourced from powertrain and road surface irregularities and their fatigue strength is tightly dependent on the strength of their joints. In this paper, a FE-based force/moment method has been used for numerically predicting fatigue life of powertrain installation bracketry of a commercial truck submitted to variable amplitude loading.
2016-10-25
Technical Paper
2016-36-0172
João Fernando Mendes Amparo, Marcos Rogério Santos Barbetti, Paulo Alexandre Galarce Zavala, George Ballardie, Roberto Moriya
Abstract This paper has the objective to present the study made on a front wheel drive passenger car with “3 Points Pendular Mounts System” to minimize the “Power Hop effect” (powertrain forced oscillation) and reduce the loads on Powertrain Mounts System. In this study, we used the Taguchi Method (Design of Experiments) to optimize the number of tests performed to evaluate the influence of powertrain mounts system design characteristics, as well as axle shafts stiffness, and tire/wheels assemblies size. The data acquisition work was all done in a physical hardware (vehicle) on test track used instrumented parts and load cells. Accelerometers were used in previous tests to get qualitative understanding of the behavior of all interface components (mounts and wheels hubs) during the power hop event.
2016-04-05
Technical Paper
2016-01-0439
Tianqi Lv, Peijun Xu, Yunqing Zhang
Abstract The powertrain mounting system (PMS) plays an important role in improving the NVH (Noise, Vibration, Harshness) quality of the vehicle. In all running conditions of a vehicle, the displacements of the powertrain C.G. should be controlled in a prescribed range to avoid interference with other components in the vehicle. The conventional model of PMS is based on vibration theory, considering the rotation angles are small, ignoring the sequence of the rotations. However, the motion of PMS is in 3D space with 3 translational degrees of freedom and 3 rotational degrees of freedom, when the rotation angles are not small, the conventional model of PMS will cause errors. The errors are likely to make powertrain interfering with other components. This paper proposes a rigid body mechanics model of the powertrain mounting system. When the powertrain undergoes a large rotational motion, the rigid body mechanics model can provide more accurate calculation results.
2016-04-05
Technical Paper
2016-01-1321
Masahiro Fukazawa, Tsuyoshi Murao, Shingo Unigame
Abstract The CAE method to predict the vibration transfer function of the hydraulic engine mount on a vehicle with sufficient precision and calculation time without prototype cars was developed. The transfer function is given in the following steps. First, rubber deformation form under the power train weight loaded must be predicted. It’s obtained by using a reduction model of an engine mount, as a unit, which doesn’t have its fluid sealed inside, with the technique to get the static spring characteristics in a non-linear relationship. Second, Young’s modulus and structural damping coefficient for the deformed rubber must be given. As for these characteristics, ignoring the relations between these values and strain, the constant values are used. This considerably reduces computation time and model size. Next, the reduction model and the fluid model have must be combined to express actual product. In this step, coupled analysis for fluid and structure is used.
2016-04-05
Journal Article
2016-01-0192
Alaa El-Sharkawy, Ahmed Uddin
Abstract Engine mount is one of the temperature sensitive components in the vehicle under-hood. Due to increasing requirements for improved fuel economy, the under-hood thermal management has become very challenging in recent years. In order to study the effects of material thermal degradation on engine mount performance and durability; it is required to estimate the temperature of engine mount rubber during various driving conditions. The effect of temperature on physical properties of natural rubber can then be evaluated and the life of engine mount can be estimated. In this paper, a bench test is conducted where the engine mount is exposed to a step change in the environment around it, and the temperature of the rubber section is recorded at several points till a steady state temperature is reached. A time response curve is generated, from which a time constant is determined.
2016-04-05
Journal Article
2016-01-0413
Umud Esat Ozturk, Lutfi Ucar, Kaveh Shahidi, Nuri Ersoy, Onur Zobi, Umit Bagdat, Rıfat Yanarocak, Serkan Elmalı
Abstract Internal combustion engines are attached on the vehicle body using engine mounts composed of two cast iron brackets and a rubber isolator connecting them. Engine mount road load identification during vehicle durability tests on proving ground is a critical task for engine mount development. Using standard multi-axial load-cell is not possible unless major design revisions on the vehicle body or engine block are done. Using wheel force transducers and vehicle dynamic simulation tools need extensive model tuning work to get accurate load information. Hence, a custom multi-axial load-cell design is preferred for the engine mount load identification of a BCar I4 engine. The developed load-cell engine mount bracket can be installed without doing any design changes on the vehicle. Design, durability analysis, instrumentation, calibration and vehicle installation of custom designed six degree of freedom multi-axial load cell have been performed.
2015-11-17
Technical Paper
2015-32-0727
Akiyuki Yamasaki, Teruaki Yamamoto, Kazumasa Hisada, Hiroshi Nakahara, Takumi Kawasaki
This paper describes an engine mount system that achieves reduced vibration on an industrial type utility vehicle. First the vibration level and direction of the inline three cylinder engine installed in the vehicle was analyzed and based on these results a mount layout that leads to a reduced level of vibration felt by the passengers was developed. Next, this was applied on an actual vehicle and spring characteristics were designed for each mount. The actual spring constants were set such that when considering the engine to be a rigid body, the resonance frequency thereof occurs at an engine speed lower than idle and in addition were set to ensure component strength relative to driving forces and inertial forces that act while the utility vehicle is being driven. Lastly, achievement of significant vibration reduction was confirmed on an actual vehicle showing that this engine mount system is effective at reducing vibration.
2015-09-29
Technical Paper
2015-01-2757
Deepak Anand Subramanian, Nithya Sridhar, N. Obuli Karthikeyan, V. Srinivasa Chandra
Abstract The Indian automotive sector is experiencing a major shift, focusing predominantly towards the levels of quality, reliability and comfort delivered to the customer. Since the entry of global players into the market, there is a rising demand for timely product launches with utmost priority to reliability. In any vehicle, engine isolation systems play a critical role in isolating the engine vibrations from the vehicle chassis. This project details on how testing can aid in reducing the launch time as well as estimating the reliability of the component when used in a different application/vehicle. It proposes a methodology to formulate a life model for the engine mount considering various combinations of predictor parameters affecting its performance over its design life. In order to maintain good correlation with the field (which considers the loading pattern and the environmental factors), warranty data was analyzed and the predictors were chosen appropriately.
2015-09-22
Technical Paper
2015-36-0325
Wagner Rossi de Sá, Henrique Leandro Silveira, Robson Pederiva
Abstract This work develops the kinematic and dynamic analysis of a diesel engine mounted on cushions, obtaining the nonlinear equations of motion and its integration has the vibration responses of the engine. With the system response values, are simulated different position settings and characteristics of the cushions for the qualitative and quantitative evaluation of the dynamic changes occurring in the system.
2015-09-15
Journal Article
2015-01-2621
Douglas Leicht
Abstract Aviation regulations requires that engine mounts, and other flight structures located in designated fire zones must be constructed of fireproof material so that they are capable of withstanding the effects of fire. Historically, steel is defined as being inherently fireproof, however, titanium was not. Therefore, a fireproof test was conducted using 6AL-4V titanium structure for the attachment of the propulsion system on a mid-size business jet to satisfy FAA Federal Aviation Requirement 25.865. To determine if the titanium structure would be able to support normal operating loads during the fire event, finite element analysis was performed on the titanium structure simulating the fire test. The fire test simulates a fire on the aircraft from the propulsion system by using a burner with jet fuel exposing the component to a 2000 °F (1093°C) flame. The 2000 °F (1093°C) Flame is calibrated based on FAA Advisory Circular AC20-135.
2015-06-15
Technical Paper
2015-01-2231
Masashi Arakawa, Miho Nakatsuka, Hiroo Yamaoka
Abstract To analyze vibration generated from the gears caused by meshing error, a new prediction methodology has been developed for vibration transmitted through the engine mounts from the transmission housing. This paper focuses on the left engine mount and brackets attached to the transmission housing of a compact front-wheel drive (FWD) vehicle that connect the transmission housing to the body structure. In this methodology, a modeling technique that incorporates the dynamic characteristics of rubber mounts and brackets is indispensable. A new simulation technique deals with a detailed rubber mount FE model that considers the contact area at the attachment point of the mount and brackets. The methodology is able to estimate vibration with high accuracy by taking into account dynamic characteristics such as surging for the rubber mount, and using the actual contact area confirmed by pressure sensitive paper for the vehicle FE model.
2015-06-15
Technical Paper
2015-01-2354
Xiao-Ang Liu, Zhaoping Lv, Wenbin Shangguan
Abstract The inline 3-cylinder engine is taken as an object, the imbalance resultant rotating inertia moment and resultant reciprocating inertia moment generated by piston-crank mechanisms are analyzed. The balance theories of two different balance methods are presented and the additional moment generated through each method is derived. Three different balance conditions are proposed. The imbalance moments and mount reaction forces in each condition are calculated and compared. The powertrain mounting system design method is developed. The optimal mount stiffness not only satisfy the powertrain's natural frequencies and energy distributions but also meet the requirement for mount reaction forces in “50% balance condition”.
2015-06-15
Technical Paper
2015-01-2280
Bernd Philippen, Roland Sottek
Abstract Transfer Path Analysis and Synthesis is a widely-used troubleshooting and engineering method in the development process of a car. An engine TPA model should include the engine mounts because they are important elements of the structure-borne paths from the engine to the driver's ears. This allows identifying if the structure, the sound radiation or the mount is a weak point of the transmission. A mount can be characterized, e. g., by a mount attenuation function, a four-pole model, or a simple parametric mount model. If the mount characteristics are known, the influence of a different mount on the structure-borne sound can be virtually predicted without a real modification. The mount characteristics could be determined on special test rigs but the transferability to the real situation is often questionable because the same boundary conditions on the test rig and in the car are difficult to guarantee.
2015-06-15
Journal Article
2015-01-2252
Haixin Dai, Weikang Jiang, Yuanyi Huang
Abstract Engine mounts play important roles in interior noise of automobiles. Decoupling optimal design of mounts has been researched for long, but reducing vibration power into body transmitted from engine can be a more intuitive way to improve NVH performance. Some approaches for minimizing transfer power through engine mounts based on finite element model were reported, whose disadvantages are lack of data and inaccuracy at high frequency in some cases. To get an analytic formula of transmitted power, a model considering coupled vibration between the body and the engine is presented here. An admittance function matrix is used to describe the dynamic relationship between the mounting points on the body side. Based on this admittance matrix measured on the full vehicle, and excitation forces identified with acceleration data measured on all mounts, the vibration equation of the coupled model can be established by using Lagrange's methodology.
2015-04-14
Technical Paper
2015-01-0609
Yan Xie, Weiguo Zhang, Xingxing Feng, Yunqing Zhang
Abstract Powertrain mounting system (PMS) often operates with some degrees of uncertainty. These uncertainties may result from poorly known or variable parameters such as mount stiffness, or from uncertain inputs. For realistic predictions of the system behavior, the PMS models have to account for these uncertainties. To this end, the Chebyshev interval method is applied to study the uncertain characteristics of PMS. In the PMS, the location and orientation of each mount are off-design variables due to the space limitation of the powertrain. The stiffness coefficients of the mounts are considered as interval variables. The lower bounds and upper bounds of natural frequencies and the mode kinetic energy distributions of PMS are obtained using the Chebyshev interval analysis method. As a comparison, the scanning method is used to validate the interval method.
2015-04-14
Technical Paper
2015-01-1670
Can Tao, Hengjia Zhu, Peijun Xu, Yunqing Zhang
Abstract Hydraulic Engine Mount (HEM) is widely used in vehicle Powertrain Mounting System (PMS) for vibration isolation. The dynamic performances of an HEM are strongly frequency dependent. A Five-Parameters Fractional Derivative model is used to describe the dynamic properties of an HEM. A 1/4 car model is applied to evaluate the effect of frequency-dependent dynamic stiffness which using measured data of a typical hydraulic engine mount. The excitations from engine and road are considered in the simulation. The generalized- α method is presented to solve the vehicle model with five-parameter fractional derivative model.
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