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A methodology is presented to do accelerated vibration durability test, on Electro Dynamic Shaker (EDS) by using Power Spectral Density (PSD) profile based on typical customer usage pattern. A generalized iterative procedure is developed to optimize input excitation PSD profile on EDS for simulating the exact customer usage conditions. The procedure minimizes the error between the target channels measured on road and the response channels measured on EDS. Also, response of accelerometers and strain gauges at multiple locations on the test component are arrived at based on a single input excitation using this procedure. The same is verified experimentally as well. Different parameters like strain, acceleration, etc. are simulated simultaneously. This methodology has enabled successful simulation of road conditions in lab, thereby arriving at a correlation between rig and road. The correlation obtained is based on the simulation of the same failure mode as that of the road on the rig.

Scooters are becoming increasingly popular in India. Competition in this segment has forced the product developers to put focus on development time reduction and quality improvement. Any physical failure of critical parts in the actual customer usage conditions can delay the product launch. The present study is about simulation of failure of crankcase during field trials. This involved creation of Finite Element model, evolution of proper loading and boundary conditions which capture the failure area, development of a static and an accelerated dynamic test in laboratory to reproduce the field failure, the optimization of the crankcase design through FEM to achieve acceptable stress values at critical areas and validation of these results through newly developed laboratory tests. Simultaneously, field trials, which initially produced this failure were conducted and no failures were observed. Thus, the current study has saved time of actual field trials (3∼4 weeks) after the redesign.

Two wheelers are very popular as means of transportation in ASIA. It is also used as load carrier in some places. Chassis frame is a very critical part of a two wheeler taking most of the loads coming from the roads. During the design and development stage, structural integrity of the frame needs to be established. Bump test is one of the critical life tests performed on the vehicle for evaluating the fatigue life of the frame. Normally, three to four iterations take place before frame passes this bump test. This is a time taking test process (1week per iteration) and does not guarantee the end result. In the new approach, the bump test simulation is made using ADAMS software. The ADAMS model is validated by using the axle accelerations measured in the physical bump test. Subsequently, the loads obtained from ADAMS model are used in FEM software and the stresses are predicted. The stress pattern helped in identifying the critical areas.

This project is an experimental investigation and optimization of piston slap noise in small two-stroke gasoline engine. Piston slap is one of the most significant mechanical noise sources in an internal combustion engine. It is a dynamic impact phenomenon between the piston and the cylinder block caused by changes in the lateral forces acting on the piston. The change in cylinder block vibration level caused by the piston impact is considered as a measure of piston slap during this experiment. The intensity of piston slap is measured in terms of vibration level in ‘g’ units, by means of accelerometers mounted on the cylinder block with Top Dead Center (TDC) and Bottom Dead Center (BDC) marker. For the design of low noise engines, all the major parameters, which contribute to piston slap, are listed and the critical four are examined through additional experiments.

This paper discusses the development of a control strategy, for a CVT that operates in combination with a mechanically throttle controlled engine, for optimal performance of the powertrain in terms of fuel economy, emissions and driveability. A concept design of an electronically controlled CVT for a quadricycle application is conceived. A lumped mass simulation model of the concept vehicle along with the powertrain was created in MATLab/Simulink. An optimal control strategy is developed and implemented in the simulation model to predict the performance and compare with that of the manual transmission.

A methodology is presented to obtain loads coming on the handle bar of a motorcycle of one model and calculating generic loads from the same for all other motorcycle models. The handle bar of a motorcycle of model M1 was instrumented with strain gages and calibrated for vertical and horizontal loads. The instrumented handle bar was assembled on the vehicle and data was collected on the test rig in laboratory. The vertical and horizontal loads acting on the handle bar, on test rig was obtained based on the calibration performed. The loads thus obtained are for a particular motorcycle model M1 and is dependent on the wheel loads of that motorcycle. These loads were converted into generic load cases, which are applicable for all models of motorcycles. The generalized loads thus generated were used in predicting the fatigue life of handle bar of a different motorcycle model (M2) using FE analysis and MSC fatigue.

This paper aims at the estimation of dynamic wheel loads of a two-wheeler through mathematical modeling that will aid during the initial stages of product development. A half car model that represents a two-wheeler was used for this purpose. Road displacements were given as input to the model and the wheel loads estimated. Actual road data obtained from two-poster rig was used as input to the model thereby making it possible to calculate the wheel loads for different customer usage conditions on different roads. In this paper, a severe rough road was chosen for verification of the model with that of the rig as the rider dynamics on such roads are the most difficult to simulate even on the rigs. The estimated values from model were verified with those measured using a two-poster rig for the same road displacement. Attempt has been further made to establish a correlation between the ride comfort predictions from the model and the two-poster rig.

In recent times gearless scooters are becoming popular means of transport in ASIA because of their ease of handling in crowded traffic and superior comfort over motorcycles. Major difference, which is contributing for least vibrations incase of scooters is mechanism of engine mounting on the frame. In most of the cases motorcycle engines are rigidly fixed to the frame where as in case of scooters engine will be swinging with respect to frame. It is easy to design muffler mounting for fixed engines. Since there is no relative motion between engine and frame for motorcycle both can be fixed to frame. Swinging scooter engine demands muffler mounting directly on engine. These direct mounts may include bosses, brackets, and bolts. While useful for their intended purpose, it is possible that vibrational energy can pass between the exhaust components and the engine through this direct mounting.

In order to improve the performance and fuel economy of a reciprocating engine, it is important to reduce the overall engine frictional losses. In this paper, author conducts an experimental study on the friction characteristics due to pumping loss, valve-train system, piston assembly, auxiliaries and transmission for a 110cc, single cylinder 4-stroke gasoline engine using frictional strip-down analysis. Friction strip-down method is commonly used to investigate the frictional contribution of various engine elements at high speeds and for better understanding of the make-up of the total engine friction. The engine friction measurements for the particular engine are carried out on a motoring test rig at different engine speeds. In addition, the effect of engine operating parameters such as oil temperature and oil quantity in engine sump is also presented in detail.