SHAPE OPTIMIZATION OF A TWO WHEELER SUSPENSION WITH DIFFERENT CROSS SECTIONS

The two-wheeler chassis consists of the frame, suspension, wheels and brakes. The chassis is what truly sets the overall style of the two-wheeler. Automotive chassis is the main carriage systems of a vehicle. The frame serves as a skeleton upon which parts like gearbox and engine are mounted. It can be made of steel, aluminum or an alloy. It keeps the wheels in line to maintain the handling of the two-wheeler.The frame of a motor vehicle supports all the drive assemblies, i.e. the engine, gearbox and axles (front and rear). In addition the suspension and steering systems and the shock absorbers are attached to it. The appropriate body is fixed to the chassis. It is essential that the frame should not buckle on uneven road surfaces and that any distortions which may occur should not be transmitted to the body. The frame must therefore be torsion−resistant. The frame of a motor vehicle is the load bearing part of the chassis which supports all forces (wheel forces) and weights. It should be as rigid as possible.The main aim of the project is to model a frame of a two wheeler using 3D modeling software Pro/Engineer. Two models of suspension are designed for pipe type and rectangular cross sections.Considering the frame as a beam, calculations are done to determine the displacement and stress by applying loads.To validate the strength of two models, Structural analysis is done by applying the wheel forces. In this analysis ultimate stress limit for the model is determined. Analysis is done for frame using two materials steel and aluminum to verify the best material for frame. Modal analysis is also done to determine natural frequencies of suspension frame. Analysis is done in ANSYS software.Comparison is done mathematically and by FEA analysis. And also we can validate the better cross section and material for suspension frame.

Dynamic analysis of the interactions between a low-to-medium-speed maglev train and a bridge: Field test results of two typical bridges

The rated suspension gap of a low-to-medium-speed maglev train with electromagnetic suspension is normally 8–10 mm. However, while either passing over a bridge or being stationary on one, the maglev train deforms the bridge and therefore alters the suspension gap. Hence, a problem arises due to coupled vibrations between the maglev train and its supporting bridge. In the study reported here, field experiments were conducted on the Chinese Changsha maglev line, which was the first commercial low-to-medium-speed maglev line in China. The focus is on two types of pre-stressed double-track concrete bridges on the maglev line. One is a simply supported girder with a span of 25 m, while the other is a continuous girder designed as 25 + 35 + 25 m. The accelerations and vertical dynamic deflections of the two bridges at midspan were measured while a five-module low-to-medium-speed maglev train with electromagnetic suspension either passed over or was stationary on either bridge, as were the accelerations of the car body and the suspension frame. The basic dynamic characteristics of the two bridges are analysed and compared with those of bridges in various typical maglev lines. The vibration characteristics of the two bridges, the car body and the suspension frame are studied in the time and frequency domains for the maglev train running at normal speeds, low speeds and when stationary. The influences of the speed on the dynamic characteristics are discussed. Some comparisons with other studies are also carried out, including the effects of bridge parameters on the coupled vibrations and the running stability of a low-to-medium-speed maglev and a CRH2C wheel/rail train. Significant conclusions are drawn from the analysis: increasing the rigidity and mass of the bridge can significantly reduce its vibration; increasing the span and deflection of the bridge increases the vibrations of the car body and the suspension frame; the dynamics of the maglev vehicle and bridges are different when the maglev train runs at normal speeds (more than 30 km/h), low speeds (less than 30 km/h) and when being stationary. The running stability of a low-to-medium-speed maglev train is better than that of a CRH2C high-speed train. The present study provides a test basis for further research on the mechanisms for coupled vibrations of maglev train–bridge systems.

Improvement of Tuning Fork Gyroscope Drive-mode Oscillation Matched using a Differential Driving Suspension Frame

<p>This paper presents a novel design of a vibration tuning fork gyroscope (TFG) based on a differential driving suspension coupling spring between two gyroscopes. The proposed TFG is equivalent to a transistor differential amplifier circuit. The mechanical vibrations of driving frames are, therefore, well matched. The matching level depends on stiffness of spring. When three various TFG structures respond to differential stiffness of spring, their the driving frame mechanical vibration is well matched in case the input excitation driving differential phase is less than 3.5°, 2.5°, and 4°, respectively. The fabricated tuning fork gyroscope linearly operates in the range from -200 to +200 degree/s with the resolution of about 0.45 mV/degree/s.</p>

Improvement of Tuning Fork Gyroscope Drive-mode Oscillation Matched using a Differential Driving Suspension Frame

<p>This paper presents a novel design of a vibration tuning fork gyroscope (TFG) based on a differential driving suspension coupling spring between two gyroscopes. The proposed TFG is equivalent to a transistor differential amplifier circuit. The mechanical vibrations of driving frames are, therefore, well matched. The matching level depends on stiffness of spring. When three various TFG structures respond to differential stiffness of spring, their the driving frame mechanical vibration is well matched in case the input excitation driving differential phase is less than 3.5°, 2.5°, and 4°, respectively. The fabricated tuning fork gyroscope linearly operates in the range from -200 to +200 degree/s with the resolution of about 0.45 mV/degree/s.</p>

Portable Suspension Frame

No abstract available.