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The importance of style design has increased tremendously in Indian two-wheeler market and at the same time new styles become obsolete in a short period. This rapidly changing market trend demands simulation methodology to evaluate the component for various loads in the design stage itself to reduce the product development cycle time. Aluminum cast footrest is preferred for better looks compared to sheet metal or tubular footrest. Normal load carried by the footrest is quite low but consideration should be given for severe loads experienced by the footrest during adverse conditions, like for example, hitting against potholes at high speed. In this current work an initial design of a die-cast footrest bracket with a particular geometric configuration and material was analyzed using finite element analysis for static and dynamic loads.

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.

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.

Two wheelers are becoming increasingly popular in India. Competition in this segment has made the product developers to develop the vehicles with short time without compromising durability. Vibration Fatigue Analysis is an advanced technique to evaluate the life of components undergoing vibration, thereby the drastic reduction in durability evaluation time. Front fender is a styling component generally made with plastic material and undergoes vibrations. Therefore, it is very difficult to design the fender based only on static load cases. Vibration fatigue analysis using Finite Element Method (FEM) is used to ensure the durability in design stage itself. Various customer usage modes of the vehicle are considered. Accelerometers and strain gauges are mounted on the fender on appropriate locations. First, the instrumented fender is mounted on the electro dynamic shaker. The fender is excited with sinusoidal inputs.

Automotive manufacturers today are faced with the challenge of producing high quality products in a short time. In such a competitive environment, higher reliability gives competitive edge to the manufacturers. However, higher reliability involves increased durability testing on their part, which leads to an increase in development time and cost. Therefore, it becomes imperative to re-look the existing test standards as against the actual customer usage conditions thereby optimizing the testing time and the development costs. With that goal in mind, this paper elaborates the procedure used for establishing a correlation between three structural durability test rigs and customer usage on the road. Two different approaches were adopted to arrive at a final correlation between the structural test rigs and the customer usage on the road. The first approach arrives at a one to one correlation based on the failure modes of different components observed on each of the test rigs and in field.

Brake system is one of the most important safety related sub systems for any automobile. This requires all auto majors to put more effort in design optimization of brake system and exhaustive evaluation for the same. On-road evaluation of brakes is time consuming process and has other shortfalls like unsafe riding conditions, less repeatability, limitation of brake input force, speed, less control in test conditions, requirement of special track etc. Normal lab testing for brake system has several drawbacks like imprecise inertia simulation, more testing time, uncontrolled test environment, partial system level evaluation, huge rotating mass which may lead to unsafe operating conditions, frequent maintenance, etc. This paper describes about the methodology adopted, efforts involved and results obtained by developing an accelerated evaluation system for brakes as a complete sub system in laboratory.

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.

Fatigue life prediction is the most promising technique for drastic reduction of durability evaluation time, which is a critical element in the product development cycle. By using this technique, it is possible to reduce development time and cost, identify failure modes early in the development cycle, and design the component for optimum life. This paper discusses the optimisation of an important two-wheeler component namely, the center stand, using fatigue life prediction techniques. Also, it aims at establishing correlation among various customer usage patterns, accelerated endurance tests, and fatigue life prediction results using both experimental data and finite element (FE) models.

In the recent years, reduction of new product development time is the major challenge for all auto manufacturers to sustain in the stiff competition. Durability evaluation is one of the most time consuming element in New Product Development (NPD) process. Finding a generic solution for commonly faced design issues is a key factor for dramatic reduction in evaluation time. Testing time reduction can be achieved by breaking down the evaluation into subsystem level and component level instead of complete vehicle. But the maximum time reduction can be achieved only through durability evaluation at material / process level. This type of evaluation yields a generic solution, which results in establishing all-purpose design and material selection criteria during initial stage of development. By adopting this technique, separate evaluation of vehicles/ subsystems for improvements in material, welding, process etc. can be avoided.

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.