“…The spring damper in the SMF in this study features a two-stage stiffness and long travel angle that is beneficial for filtering torsional vibration from the engine to transmission (Couderc et al, 1998; Wei et al, 2020). Figure 4(a) shows the relationship between the relative rotation angle of element θθ=φ1−φ2 and the transmitted torque Mc.…”
Section: Dynamic Modeling and Analysis Of Driveline Torsional Vibrationmentioning
confidence: 99%
“…Kc1 and Kc2 are the first and second stage torsional stiffnesses, respectively, Hd1 and Hd2 are the first and second stage hysteresis torque, respectively, and θmax is the maximum torsional angle. σ is a smoothing factor, with σ=1000 according to Wei et al (2020).Figure 4.Nonlinear characteristic of a spring damper in the single-mass flywheel.…”
Section: Dynamic Modeling and Analysis Of Driveline Torsional Vibrationmentioning
Dual-clutch transmissions (DCTs) are very sensitive to torsional vibration and easily produce rattle noise if a single-mass flywheel (SMF) with a conventional torsional damper or a dual-mass flywheel (DMFW) is used in the vehicle. Only a DMFW combined with a centrifugal pendulum vibration absorber (CPVA) can eliminate rattle problem; however, this solution is expensive. Alternatively, a SMF with a CPVA is proposed to eliminate the DCT rattle issue, which could be a feasible and cost-effective solution free of side effects introduced by DMFWs. The vibration absorption principle of different types of pendulums and the rotor dynamic model are investigated to study the feasibility of a SMF with CPVA in a DCT vehicle. A seven-degree-of-freedom nonlinear lumped torsional vibration model is proposed to evaluate the torsional vibration attenuation performance of different configurations of torsional dampers and CPVAs. As per the model calculation results, the bifilar pendulum features the best attenuation performance compared with the circular and cycloid pendulums. The effect of pendulum parameters on attenuation is studied, and the optimized values are obtained. The SMF and optimized bifilar CPVA combination can satisfy the no-rattle requirements in vehicle relative to the DCT in-vehicle no-rattle threshold. A vehicle assessment on roads using physical pendulum prototypes indicates that the SMF with CPVA can be used as an alternative, cost-effective solution for DCTs, instead of the expensive DMFW with CPVA solution.
“…The spring damper in the SMF in this study features a two-stage stiffness and long travel angle that is beneficial for filtering torsional vibration from the engine to transmission (Couderc et al, 1998; Wei et al, 2020). Figure 4(a) shows the relationship between the relative rotation angle of element θθ=φ1−φ2 and the transmitted torque Mc.…”
Section: Dynamic Modeling and Analysis Of Driveline Torsional Vibrationmentioning
confidence: 99%
“…Kc1 and Kc2 are the first and second stage torsional stiffnesses, respectively, Hd1 and Hd2 are the first and second stage hysteresis torque, respectively, and θmax is the maximum torsional angle. σ is a smoothing factor, with σ=1000 according to Wei et al (2020).Figure 4.Nonlinear characteristic of a spring damper in the single-mass flywheel.…”
Section: Dynamic Modeling and Analysis Of Driveline Torsional Vibrationmentioning
Dual-clutch transmissions (DCTs) are very sensitive to torsional vibration and easily produce rattle noise if a single-mass flywheel (SMF) with a conventional torsional damper or a dual-mass flywheel (DMFW) is used in the vehicle. Only a DMFW combined with a centrifugal pendulum vibration absorber (CPVA) can eliminate rattle problem; however, this solution is expensive. Alternatively, a SMF with a CPVA is proposed to eliminate the DCT rattle issue, which could be a feasible and cost-effective solution free of side effects introduced by DMFWs. The vibration absorption principle of different types of pendulums and the rotor dynamic model are investigated to study the feasibility of a SMF with CPVA in a DCT vehicle. A seven-degree-of-freedom nonlinear lumped torsional vibration model is proposed to evaluate the torsional vibration attenuation performance of different configurations of torsional dampers and CPVAs. As per the model calculation results, the bifilar pendulum features the best attenuation performance compared with the circular and cycloid pendulums. The effect of pendulum parameters on attenuation is studied, and the optimized values are obtained. The SMF and optimized bifilar CPVA combination can satisfy the no-rattle requirements in vehicle relative to the DCT in-vehicle no-rattle threshold. A vehicle assessment on roads using physical pendulum prototypes indicates that the SMF with CPVA can be used as an alternative, cost-effective solution for DCTs, instead of the expensive DMFW with CPVA solution.
“…The torsional vibration of the powertrain system significantly influences the fatigue life of rotary components and the noise, vibration, and harshness (NVH) performance of the vehicle. [1][2][3][4] Even though the torsional damper is integrated in the clutch, 5 the torsional vibration problems of the powertrain system, such as the driveline shuffle, [6][7][8] clutch judder, [9][10][11][12] gear rattle, 13,14 and powertrain torsional resonance, 15,16 are still encountered under the excitation of the fluctuating torque of the engine. Among the vibration problems above, the powertrain torsional resonance is one of the most harmful, because it not only induces the abnormal 1 vibration and booming noise in the cabin, but also accelerates the fatigue damage of driveline components.…”
The vehicle acceleration process is often accompanied by torsional vibration of the powertrain system. Poor torsional vibration performance significantly influences the driving comfort of the vehicle and the reliability of powertrain components. Compared to passenger cars, commercial vehicles, especially the heavy-duty truck, exhibit more complicated vibration behaviors during acceleration due to the multiple power branches, various gears, and different working conditions. This article presents systematic research on the modeling method, vibration characteristics, mechanism, and influence factors of the torsional resonance of the heavy-duty vehicle during acceleration. A 16-DOF powertrain model considering multiple nonlinearities of the system is proposed and experimentally validated reliable. Numerical and experimental studies are carried out to investigate the vibration characteristics and mechanism of the heavy-duty vehicle powertrain, and the modal energies and parameter influences are also discussed. Besides, an optimization example is presented to analyze the potential vibration attenuation performance of optimizing the clutch parameters. The results indicate that the overall powertrain mode of the heavy-duty vehicle tends to be aroused by the engine firing frequency during accelerating, inducing violent speed fluctuations of the powertrain components between the clutch and half-shafts. The clutch parameters have significant impacts on the powertrain resonance, and the vibration amplitude of the powertrain system can be effectively attenuated to acceptable levels by optimally designing the clutch parameters.
“…Remedies that suppress rattle are mainly categorised as external and internal measures [1]. Former ones consist of the tuning of the driveline torsional dampers, in which multi-stages clutch damper [10], dual-mass flywheels [11], and centrifugal pendulum vibration absorbers [12], et al, are the common countermeasures.…”
This investigation comprehensively compared the elastic contact and the modified stiff impact models, aiming for the lightly loaded backlash-induced gear rattle. Three meshing force models in backlash are incorporated into the elastic model independently. Unlike the previous uncoupled stiff impact model, the modified impact model considers the coupling between the pinion and gearwheel. Three scenarios were investigated with different components of two internal excitations, static transmission error (STE) induced periodical backlash and the time-varying meshing stiffness (TVMS). The analytical results show that the free and forced gear motion, nonlinear characteristics and rattle severity are strongly affected by STE rather than TVMS. Two studied hydrodynamic lubricant (HDL) models show different damping effects. The forced gear motion state and rattle sensitivities show a noticeable difference below 40rad/s 2 and turn to a slight variation above 60rad/s 2 . Finally, the HDL model containing only the oil squeeze effect will likely match the experimental results. The experimentally detected STE component of the gearwheel suggests that an acceptable model should be considered in the gear rattle model.
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