scholarly journals Impact-induced vibration in vehicular driveline systems: Theoretical and experimental investigations

2005 ◽  
Vol 219 (1) ◽  
pp. 1-12 ◽  
Author(s):  
M Gnanakumarr ◽  
S Theodossiades ◽  
H Rahnejat ◽  
M Menday
Keyword(s):  
High Frequency ◽  
Experimental Investigations ◽  
Flexible Body ◽  
Experimental Measurements ◽  
Light Truck ◽  
Radiated Noise ◽  
Vibrational Response ◽  
Body Dynamics ◽  
Multi Body

The paper investigates the conditions leading to the emergence and persistence of an acute metallic noise in light-truck drivelines. Sudden demands in torque in the presence of lash zones give rise to this phenomenon, which is onomatopoeically referred to as clonk. The study of clonk requires combined rigid multi-body dynamics and flexible body oscillations. The results show high-frequency contributions in the driveline vibrational response of certain structural modes of the driveshaft pieces, which are induced by remote impact of meshing transmission teeth through backlash. The numerically predicted spectrum of vibration shows good correlation with experimental measurements of radiated noise from a dynamic drivetrain rig.

Quasi-Variational Principles of Single Flexible Body Dynamics

2010 ◽  
Author(s):  
Haiyan Song ◽  
Jiansheng Zhou ◽  
Lifu Liang ◽  
Zongmin Liu
Keyword(s):  
Variational Principle ◽  
Variational Principles ◽  
Deformable Body ◽  
Rigid Body Dynamics ◽  
Flexible Body ◽  
Cross Link ◽  
Body Dynamics ◽  
Flexible Body Dynamics ◽  
Multi Body

The theoretical analysis of flexible multi-body system is a long-term and complicated problem. So the single flexible body dynamics should be studied firstly. Quasi-variational principle of non-conservative single flexible body dynamics is established under the cross-link of particle rigid body dynamics and deformable body dynamics. Some important problems are studied in quasi-variational principle of non-conservative single flexible body dynamics. The vibration problem of unrestrained beam can be solved very well by using quasi-variational principle.

Design of a miniature modular inchworm robot with an anisotropic friction skin

Robotica ◽  
2018 ◽  
Vol 37 (3) ◽  
pp. 521-538 ◽  
Author(s):  
Wael Saab ◽  
Peter Racioppo ◽  
Anil Kumar ◽  
Pinhas Ben-Tzvi
Keyword(s):  
High Frequency ◽  
Experimental Validation ◽  
Anisotropic Friction ◽  
Confined Spaces ◽  
Model And Simulation ◽  
Body Dynamics ◽  
Two Generations ◽  
Simulation Results ◽  
Multi Body ◽  
Friction Analysis

SUMMARYThis paper presents the design, analysis, and experimental validation of a miniature modular inchworm robot (MMIR). Inchworm robots are capable of maneuvering in confined spaces due to their small size, a desirable characteristic for surveillance, exploration and search and rescue operations. This paper presents two generations of the MMIR (Version 1—V1 and Version 2—V2) that utilize anisotropic friction skin and an undulatory rectilinear gait to produce locomotion. This paper highlights design improvements and a multi-body dynamics approach to model and simulate the system. The MMIR V2 incorporates a slider-crank four-bar mechanism and a relative body revolute joint to produce high-frequency relative translation and rotation to increase forward velocity and enable turning capabilities. Friction analysis and locomotion experiments were conducted to assess the systems performance on various surfaces, validate the dynamic model and simulation results, and measure the maximum forward velocity. The MMIR V1 and V2 were able to achieve maximum forward velocities of 12.7 mm/s and 137.9 mm/s, respectively. These results are compared to reported results of similar robots published in the literature.

Robust multi-steps input command for liquid sloshing control

2021 ◽  
pp. 107754632110177
Author(s):  
Abdullah Alshaya ◽  
Adel Alshayji
Keyword(s):  
Liquid Sloshing ◽  
Flexible Body ◽  
Transient Vibration ◽  
Resonant Frequencies ◽  
System Parameters ◽  
Input Shaper ◽  
Body Dynamics ◽  
Time Optimal ◽  
Multi Body ◽  
Input Command

A robust input command based on multiple steps for eliminating the residual vibrations of a multimode linear system is proposed. Only the system resonant frequencies are needed to determine the step magnitudes in the shaped command. The command duration is selectable to help in designing an optimum command that compensates between the reduction in the transient vibration, the enhancement in the command robustness, and the increase in the total maneuver time. The induced transient and residual sloshing oscillations of a suspended water-filled container are suppressed using the proposed command. The dynamics of the sloshing is numerically simulated using finite element method that accommodates the interactions between the fluid, structural, and multi-body dynamics. A short move time penalty is incurred with the price of significant reduction in the liquid sloshing. The performance of the shaped command to the system parameters and the robustness to their uncertainty are investigated. An improved robust input command in the presence of uncertainties in the cable length and water depth is also introduced. The effectiveness and excellence of the proposed command is demonstrated through a comparison with multimode zero-vibration input shaper and time-optimal flexible-body control.

Elasto-Multibody Dynamic Simulation of Impact Induced High Frequency Vehicular Driveline Vibrations

2003 ◽  
Author(s):  
M. Gnanakumarr ◽  
S. Theodossiades ◽  
H. Rahnejat ◽  
M. Menday
Keyword(s):  
High Frequency ◽  
Impact Testing ◽  
Vibration Monitoring ◽  
Vibrational Response ◽  
Multibody Dynamic ◽  
High Contribution ◽  
Noise Vibration ◽  
Experimental Values ◽  
Multi Body ◽  
Body Dynamic

This paper investigates an NVH (Noise, Vibration and Harshness) phenomenon, which occurs as a load reversal in the presence of lashes in the driveline and is known in industry as clonk. A combined study of rigid multi-body dynamic analysis and flexible body oscillations, using super-element FEA techniques is being deployed. The results show high contribution in the driveline vibrational response of certain structural modes of the driveshaft pieces, induced by remote impacting of meshing transmission teeth trough backlash. The predicted spectrum of vibration shows good conformance with previously obtained experimental values, for both impact testing of the driveshaft pieces, as well as those obtained by vibration monitoring of experimental rigs (Vafaei et al, 2001).

scholarly journals Root cause identification and physics of impact-induced driveline noise in vehicular powertrain systems

2005 ◽  
Vol 219 (11) ◽  
pp. 1303-1319 ◽  
Author(s):  
S Theodossiades ◽  
M Gnanakumarr ◽  
H Rahnejat
Keyword(s):  
Rear Wheel ◽  
Experimental Investigations ◽  
Root Cause ◽  
Wheel Drive ◽  
Body Dynamics ◽  
Parametric Studies ◽  
Root Cause Identification ◽  
Multi Body ◽  
Experimental Rig ◽  
Shed Light

Numerical and experimental investigations shed light on the root causes leading to the emergence and persistence of an acute metallic noise in rear wheel drive light truck drivelines. Sudden demands in engine output torque combined with the presence of lash zones give rise to a phenomenon that is onomatopoeically referred to as clonk. Its multi physics nature requires a comprehensive study, which includes rigid multi-body dynamics, flexible body oscillations, and noise radiation computation. The verification of numerical results is achieved through the design and implementation of a transient dynamic experimental rig, which comprises the complete drivetrain from the engine flywheel to the rear axle. Parametric studies reveal high-frequency contributions in the driveline vibration response of certain structural modes of the driveshaft pieces, which are induced by remote impact of meshing transmission teeth through backlash. The numerically predicted spectrum of vibration is in good qualitative agreement with the experimental measurements. Combined study of the aforementioned results reveals the components that amplify the clonk noise.

Modeling and Simulation Analysis of Certain Vehicular Gatling Gun

2013 ◽  
Vol 275-277 ◽  
pp. 2467-2470
Author(s):  
Tao Li ◽  
Rui Lin Wang ◽  
Long Bo Sheng
Keyword(s):  
Simulation Analysis ◽  
Flexible Body ◽  
Response Characteristics ◽  
Vehicle Velocity ◽  
Impact Position ◽  
Body Dynamics ◽  
Velocity Condition ◽  
Flexible Body Dynamics ◽  
Multi Body ◽  
Exterior Ballistics

To study the influence of barrel’s deformation and vehicle velocity to certain vehicular Gatling gun, a virtual simulation with rigid-flexible coupling was established by using ADAMS/Flex module based on rigid multi-body dynamics and flexible body dynamics theories. Considering the interaction of the tires and road surface, vehicle and machine gun, the dynamic analysis and calculation of exterior ballistics were completed in various vehicle velocity condition, the muzzle response characteristics and impact position were obtained. The Model is testified rational, accuracy and effective by comparing simulating results with the experimental data of the velocity and displacement of barrel, which has laid the foundation for further simulation and structural optimization.

Sign in / Sign up

Export Citation Format

Share Document