Vibration and sound radiation analysis of the final drive assembly considering the gear-shaft coupling dynamics

Author(s):  
Yawen Wang ◽  
Junyi Yang ◽  
Dong Guo ◽  
Teik C Lim

A generalized dynamic model of driveline system is formulated that includes the coupling effect and gyroscopic moments of the propeller shaft and hypoid gear rotor assembly. Firstly, the dynamic models with only gear-shaft coupling, with only gyroscopic effect, and with both gear-shaft coupling and gyroscopic effect are analyzed and compared. The results show that the combined effects of the gear-shaft interaction and gyroscopic behavior have considerable influence on the system dynamic responses surrounding gear bending resonances, especially for the bearing responses. However, the gear out-of-phase torsional modes still dominate the gear mesh frequency response. Secondly, the influence of pinion bending moment of inertia, propeller shaft stiffness and bearing stiffness on the system dynamic responses are examined. The system responses are then applied to perform further vibration and acoustic analysis for an axle housing structure. Computational results reveal that NVH (noise, vibration, and harshness) refinement can be achieved by tuning the pinion bearing rotational stiffness and pinion bending moment of inertia for the example considered. This study provides an understanding of the interaction between hypoid gear pair and propeller shaft, and can be employed to enhance driveline system design.

2020 ◽  
Vol 68 (1) ◽  
pp. 48-58
Author(s):  
Chao Liu ◽  
Zongde Fang ◽  
Fang Guo ◽  
Long Xiang ◽  
Yabin Guan ◽  
...  

Presented in this study is investigation of dynamic behavior of a helical gear reduction by experimental and numerical methods. A closed-loop test rig is designed to measure vibrations of the example system, and the basic principle as well as relevant signal processing method is introduced. A hybrid user-defined element model is established to predict relative vibration acceleration at the gear mesh in a direction normal to contact surfaces. The other two numerical models are also constructed by lumped mass method and contact FEM to compare with the previous model in terms of dynamic responses of the system. First, the experiment data demonstrate that the loaded transmission error calculated by LTCA method is generally acceptable and that the assumption ignoring the tooth backlash is valid under the conditions of large loads. Second, under the common operating conditions, the system vibrations obtained by the experimental and numerical methods primarily occur at the first fourth-order meshing frequencies and that the maximum vibration amplitude, for each method, appears on the fourth-order meshing frequency. Moreover, root-mean-square (RMS) value of the acceleration increases with the increasing loads. Finally, according to the comparison of the simulation results, the variation tendencies of the RMS value along with input rotational speed agree well and that the frequencies where the resonances occur keep coincident generally. With summaries of merit and demerit, application of each numerical method is suggested for dynamic analysis of cylindrical gear system, which aids designers for desirable dynamic behavior of the system and better solutions to engineering problems.


2021 ◽  
Author(s):  
Giorgos Maneas ◽  
Erasmia Kastanidi ◽  
Ioannis Panagopoulos

<p>The EUs Water Framework Directive, was adopted on October 2000, and it has been the basis for water management in all the EU countries since then (EU-WFD, 2000). According to the EUs-WFD, the use of groundwater bodies can be considered as sustaibale only when the portion of the overall recharge not needed by the ecology is abstracted (EU-WFD, 2000). Nonetheless, there are still cases where the implementation of the EUs-WFD faces challenges, and there is a need to better communicate the above message to water users. But how can we achieve this at a local scale?</p><p>In this work, we present the example of SW Messinia, Greece, an interlinked coastal-inland area in the Eastern Mediterranean region. In this case study, the water supply for all water uses (agriculture, tourism, domestic use) depends on groundwater resources which are also the main freshwater provider to a coastal wetland with high ecological and commercial value (Birds directive 2009/147/EC; Habitats Directive 92/43/EEC). Due to man-made interventions over the last 70 years, the wetland has passed the tipping point of being brackish (Maneas et al., 2019), and at present it is characterized as saline with hypersaline conditions for nearly 30% of the year (Manzoni et al., 2020). Unless freshwater inputs are enhanced by restoring hydrologic connectivity between the wetland and the surrounding freshwater bodies, salinity in the lagoon is expected to increase even more under future drier and warmer conditions (Manzoni et al., 2020). But how can we balance between societal and ecological groundwater needs, and how future decision making can get a broader acceptance by the society?</p><p>Under COASTAL EU project (COASTAL, 2019), we use System Dynamic (SD) models for communicating with local stakeholders towards improving land-sea interactions. In this work, we present a model which describes how inland groundwater abstraction has impacts to the wetland’s salinity. The model is used as a basis for a discussion with stakeholders and the co-creation of sustainable decision making with broader acceptance.</p><div>Literature<br><div> <p>EU WFD, 2000. Available at: https://ec.europa.eu/environment/water/water-framework/index_en.html (Accessed on 20-01-2021).</p> <p>Birds Directive 2009/147/EC (2009). The European Union Birds Directive. Available online at: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=<br>CELEX:32009L0147 (accessed November 2, 2020) .</p> <p>Habitats Directive 92/43/EEC (1992). The European Union Habitats Directive. Available online at: https://ec.europa.eu/environment/nature/legislation/<br>habitatsdirective/index_en.htm (accessed September 2, 2019).</p> <p>Maneas, G., Makopoulou, E., Bousbouras, D., Berg, H., and Manzoni, S. (2019). Anthropogenic changes in a Mediterranean coastal wetland during the last century-the case of Gialova Lagoon, Messinia, Greece. Water 11:350. doi: 10.3390/w11020350 </p> <p>Manzoni, S., Maneas, G., Scaini, A., Psiloglou, B. E., Destouni, G., and Lyon, S. W. (2020). Understanding coastal wetland conditions and futures by closing their hydrologic balance: the case of Gialova Lagoon, Greece. Hydrol. Earth Syst. Sci. 24, 3557–3571. doi: 10.5194/hess-24-3557-2020</p> <p>Maneas G, Bousbouras D, Norrby V and Berg H (2020). Status and Distribution of Waterbirds in a Natura 2000 Area: The Case of Gialova Lagoon, Messinia, Greece. Front. Ecol. Evol. 8:501548. doi: 10.3389/fevo.2020.501548</p> <p>COASTAL [Collaborative Land-Sea Integration Platform] (2019). European Union’s H2020 Research and Innovation Programme Under Grant Agreement No. 773782. Available online at: https://h2020-coastal.eu/ (accessed 03 February, 2019).</p> </div> </div>


2021 ◽  
Vol 153 (A1) ◽  
Author(s):  
H Amini ◽  
S Steen

A range of model experiments have been carried out in calm water and waves for an oil spill vessel model with twin tractor azimuth thrusters at different heading angles and advance coefficients in the large towing tank at the Marine Technology Centre in Trondheim, Norway. Propeller shaft bending loads have been measured using a shaft dynamometer capable of measuring all shaft side force and bending moment components as well as propeller torque and thrust. The results include the loads on the propeller shaft with and without the presence of a ship hull model at the same heading angles and advance velocities in order to study the wake influence from the ship hull on the hydrodynamic loads. Results show that the ship hull wake has a much stronger effect on the propeller loads when the propeller is azimuthed outward from the ship hull centreline than inward. Measurements from the experiments in waves are also presented for the same thruster model in a straight-line course for both the head and following sea states under different wave conditions. Larger bending loads are found in head sea conditions compared with the following sea conditions. Generally it is found that the shaft bending loads and lateral forces are quite large, which is important to consider in the mechanical design layout and for dimensioning of components.


2019 ◽  
Vol 9 (13) ◽  
pp. 2612 ◽  
Author(s):  
Sun Yong Kwon ◽  
Mintaek Yoo

A 3D numerical model based on finite-difference approximation was formulated to predict the dynamic soil-pile-structure interaction (SPSI) in dry sand. A non-linear elastic, Mohr–Coulomb plastic soil-constitutive model was adopted for the proposed methodology with a hysteretic damping model which can simulate nonlinear behavior of soil and an interface model which can predict separation and slippage between soil and pile according to the external load condition. Simplified continuum model was used to properly simulate the semi-infinite boundary and improve analysis efficiency. The proposed numerical model was validated by comparison with experimental results performed by Yoo (2013). Thereafter, a parametric study was also carried out to investigate the complex dynamic behavior of pile foundation under varying conditions. It was demonstrated that inertial force induced by superstructure is dominant for dynamic SPSI in dry sand whereas the kinematic force induced by soil deformation is relatively insignificant. Pile peak bending moment occurs at 30% of the pile length when pile length is no longer than 5 T and at about 30% of 5 T (1.6 T) when the pile length is longer than 5 T. The pile head fixity governed the peak bending moment profile of pile and affected the dynamic responses of the system in conjunction with other factors, such as pile rigidity.


Author(s):  
Yue-Qing Yu ◽  
Qian Li ◽  
Qi-Ping Xu

An intensive study on the dynamic modeling and analysis of compliant mechanisms is presented in this paper based on the pseudo-rigid-body model. The pseudo-rigid-body dynamic model with single degree-of-freedom is proposed at first and the dynamic equation of the 1R pseudo-rigid-body dynamic model for a flexural beam is presented briefly. The pseudo-rigid-body dynamic models with multi-degrees-of-freedom are then derived in detail. The dynamic equations of the 2R pseudo-rigid-body dynamic model and 3R pseudo-rigid-body dynamic model for the flexural beams are obtained using Lagrange equation. Numerical investigations on the natural frequencies and dynamic responses of the three pseudo-rigid-body dynamic models are made. The effectiveness and superiority of the pseudo-rigid-body dynamic model has been shown by comparing with the finite element analysis method. An example of a compliant parallel-guiding mechanism is presented to investigate the dynamic behavior of the mechanism using the 2R pseudo-rigid-body dynamic model.


Mechatronics ◽  
1998 ◽  
Vol 8 (3) ◽  
pp. 255-270 ◽  
Author(s):  
Amuliu Bogdan Proca ◽  
Ali Keyhani

2014 ◽  
Vol 628 ◽  
pp. 214-218
Author(s):  
Da Peng Zhang ◽  
Wen Ming Cheng ◽  
Kun Cai

It is the most important inspection index of the deflection value for the girder of gantry crane under rated load in the overall test. In the overall test for large tonnage gantry crane which prepared for experimental weight is very difficult at the site, or even impossible perform test. In the text, it is deduced the girder deflection curve equation where considering the effects of the leg bending moment to the girder deflection When the concentrated load is applied to the position of L/2,L/3 and 2L/3 of the girder. The girder deflection value can be obtained under small load at the position of L/2,L/3 and 2L/3 of the girder and the actual moment of inertia of the girder and two side leg can be obtained. In this way, the deflection of the large tonnage gantry crane are predicted through the data of the three-position method in the small load test. Three-position small load test method provides a practical and effective method for the prediction of the girder deflection of large tonnage gantry structure.


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