AMA, Agricultural Mechanization in Asia, Africa and Latin America (AMA) (issn: 00845841) is a peer reviewed journal first published online after indexing scopus in 1982. AMA is published by Farm Machinery Industrial Research Corp and Shin-Norinsha Co. AMA publishes every subjects of general engineering and agricultural engineering.
AMA, Agricultural Mechanization in Asia, Africa and Latin America (ISSN: 00845841) is a peer-reviewed journal. The journal covers Agricultural and Biological Sciences and all sort of engineering topic. the journal's scopes are in the following fields but not limited to:Azerbaijan Medical Journal Gongcheng Kexue Yu Jishu/Advanced Engineering Science
This study proposes a nonlinear dynamic model for a novel hydro-pneumatic suspension system of an earth-moving equipment based on traditional dynamic model with changing the properties of the elastic and damping elements with an auxiliary air chamber. And then, a quarter-vehicle dynamic model of suspension system is set up to evaluate and compare vehicle ride comfort performance between novel hydro-pneumatic suspension system and traditional hydro-pneumatic suspension system under the different operating conditions of vehicle via the root mean square (r.m.s) acceleration responses of vehicle body (awz) according to international standard ISO 2631-1:1997 and power spectral density (PSD) acceleration responses of vehicle body. The numerical simulation results indicate that awz values and peak amplitude values with the novel hydro-pneumatic suspension system respectively reduce in comparison with the traditional hydro-pneumatic suspension system. Especially, vehicle ride comfort performance with novel hydro-pneumatic suspension system significantly improves in the low frequency region of from 0.5 Hz to 10 Hz when vehicle moves on from ISO class C road surface at speed of 40km/h and full load. Finally, the different operating conditions of vehicle are chosen to verify and evaluate the effectiveness of the novel hydro-pneumatic suspension system in comparison with the traditional hydro-pneumatic suspension system. The obtained results indicate that the proposed system significantly performs better than the traditional hydro-pneumatic suspension system does in terms of ride comfort of vehicle.
The purpose of this study is to analyze the ride performance of a mining dump truck with hydro-pneumatic suspension system (HPSs). A mathematical model of hydro-pneumatic suspension strut with two oil chambers and one gas chamber is set up to determine its vertical force. And then a three-dimensional vehicle- road coupled dynamic model of a mining dump truck with 11 degrees of freedom under random road surface roughness is set up to analyze the effectiveness of HPSs in the direction of the ride comfort of vehicle. The time domain and power spectral density (PSD) of acceleration responses of the vertical driver’s seat, and the cab pitch and roll angles of a mining dump truck are chosen as objective functions to analyze the vehicle ride comfort performance of HPSs. Finally, the ride comfort performance of the HPSs under different operating conditions is analyzed respectively through objective functions. The obtained results indicate that the ride performance of a mining dump truck with HPSs are significantly improved under large amplitude excitation region of road surface roughness. Especially, the ride performance of a mining dump truck with HPSs has improved significantly at the low frequency region from 4 Hz to 10Hz in the vertical direction of driver’s seat and the cab pitch and roll angles under survey conditions.
This study proposes an analytical study in ride performance of a hydraulic cab mount system (HCMs) with the orifice and the annular orifice for a wheel loader under larger amplitude excitation of road surface roughness. First, a nonlinear dynamical model of hydraulic mount with the piecewise damping characteristic is set up to determine the vertical nonlinear force of hydraulic cab mount. And then, a half-vehicle dynamic model of a wheel loader is offered to analyze and compare the performance of hydraulic cab mount system and rubber cab mount system (RCMs) in terms of ride performance. Time domain and frequency domain acceleration responses of the vertical driver’s seat and cab pitching angle are selected as the objective functions to assess and compare HCMs performances. The study results indicate that the RMS values of acceleration responses of the vertical driver’s seat and cab pitching angle with HCMs respectively reduce by 38.16% and 29.26% in comparison with those of RCMs, and the power spectral density (PSD) value of acceleration response of the vertical driver’s seat with HCMs reduce by 55.94% in comparison with the ones of RCMs at frequency about 5Hz when vehicle moves on ISO class C road surface at the vehicle speed of 15km/h and empty load. Finally, the ride performance of HCMs in comparison with that of RCMs under various large amplitude of road surface roughness indicates that the RMS values of acceleration responses of the vertical driver’s seat and cab pitching angle respectively reduce by 30.87% and 25.70% when vehicle with full load moves on ISO class E road surface at speed of 10km/h, which improves more comfort performance under larger amplitude excitation.
This proposal study is to analyze the performance of two different types of hydro-pneumatic suspension struts for an agricultural truck. The nonlinear dynamical models of two different types of hydro-pneumatic suspension struts with two oil chambers and one gas chamber (Model 1) and with three oil chambers and one gas chamber (Model 2) are set up to determine their nonlinear forces in the vertical direction. A quarter–vehicle mathematical model of an agricultural truck is set up for the analysis of the nonlinear forces of two proposed Models under random road surface excitation which is implemented in MATLAB/Simulink platform. The obtained results indicate that the value of the root mean square (RMS) of the vertical acceleration response of vehicle body with Model 2 reduce by 5.11% in comparison with Model 1 when vehicle moves on ISO class D road surface at vehicle speed of 40 km/h and full load. Finally, both two hydro-pneumatic suspension struts are verified their ride comfort performances under various vehicle operating conditions and the obtained results also indicate that the performance with Model 2 significantly improved vehicle ride comfort in comparison with Model 1.
Nonlinear properties of fluids and hydraulic brake drive system (HBDs) components have a great effect on the braking performance. The purpose of this study is to consider their effects on the braking performance. Firstly, the theoretical basis of the elastic model of the hydraulic brake system is proposed based on the nonlinear properties of the fluids and the system compositions. And then a nonlinear mathematical model of HBDs of full power hydraulic brake system with the wet multi disc brakes for an earth- moving equipment is set up for simulation and analysis which uses Matlab/Simulink software to simulate and analyze with the set of parameters of fluid and HBDs. The simulation results show that the system responses change in accordance with the elastic properties of the fluid in the brake drive system. Finally, the fluid properties and structural parameters of HBDs are investigated their effects on the system response time and the pressure fluctuations. The obtained results show that the survey parameters of fluid and HBDs have a significant effect on the system response times and the pressure fluctuations.