Dynamic Behavior of Three-wheeled Vehicle Under Random Road Characteristics Using FEM
In general three wheelers are one of the most popular city transport vehicles in the world and particularly in developing countries especially for short hauls. In the present work finite element model of three wheeled motor vehicle chassis has been developed using ANSYS software by taking into account the chassis longitudinal/cross members, the suspensions, the axles and the tires. Modal analysis is carried on the three wheeled motor vehicle chassis using Block Lanczo's technique to obtain the natural frequencies and mode shapes. Vertical dynamic response of the three wheeled motor vehicle chassis has been carried in the frequency domain by performing the spectrum analysis using ANSYS software. When the vehicle moving at 45 kmph on different Indian and International roads, and the response is obtained at four significant points i.e. at node 2 (rear part of the chassis sprung mass), at node 8 (passenger seat position), at node 657 (rear axle) and at node 34 (steering position). The response i.e. power spectral density of acceleration is compared between the Indian and International roads and different modes which affect the passenger comfort are also discussed using spectrum analysis. Parametric study has also been carried out using the finite element model to study the effect of various parameters and to find the optimum values both quantitatively and qualitatively, in the ride response of the vehicle. Finally based on the above analysis certain recommendations are made about manufacturer point of view.
Ride Analysis of Three Wheeled Vehicle Using MATLAB/Simulink
A spatial six degree freedom mathematical model of a three wheeled vehicle (TWV) used in Asian countries has been developed using multi body system approach. The model includes suspension and tyre compliance. The model consists of a single sprung mass (vehicle body) connected to three unsprung masses (three wheels) at each corner. The suspensions and tires are modeled as springs and linear damper elements. The model consists of six degrees of freedom because the body has three degrees freedom for bounce, pitch and roll motions and each unsprung mass have bounce motion. Vertical dynamic response of the TWV has been found when the vehicle is moving at 45 kmph on random road surface. Damping ratios and natural frequencies are obtained using Eigen value analysis. Ride analysis has been carried out in the frequency domain by performing the spectrum analysis using MATLAB/Simulink.
Experimental study on bond behavior between high-strength grout and deformed steel bars
Abstract Engineers use high-strength grout to connect precast concrete members for its low shrinkage and good fluidity. This paper designed 87 central pull-out specimens using the control variable method to investigate the influence of factors on the rebar-grout bond property such as compressive strength, steel grade, bar diameter, transverse stirrups, and bond length. The test result showed that improving grout compressive strength (85.8 MPa–122.7 MPa) cannot improve the bond strength, which was different from the previous conclusions of concrete pull-out tests. Simplified formulas were presented for calculating the characteristic values of bond strength, residual strength, peak slip, and relative slip of load-holding platform based on parameter analysis. Then, a constitutive model was proposed to predict the full-range bond stress-slip curve of high-strength grout and steel bar specimens from bearing to failure. Finally, FEA models were established to evaluate the applicability and accuracy of the constitutive model.