S. V. Wong

Simulation of motorcycle crashes with w-beam guardrail: Injury patterns and analysis

Abstract This study uses computer simulations to study the impact of a motorcycle with the conventional w-beam guardrail. A three-dimensional computer simulation of a scaled hybrid III 50th-percentile male dummy mounted on a motorcycle and colliding with a w-beam guardrail is carried out. A multi-body model of the motorcycle and finite element model of the guardrail are developed using commercially available software. The simulation model is validated with a physical crash test conducted with same initial impact configurations. Impacts at speeds of 32, 48, and 60 km/h at an impact angle at 45° are considered. The predicted forces and accelerations are compared with the biomechanical limits for each body part and the risk of injury to the rider are evaluated. Speed was found to have a significant influence on the level of injury to the head, neck, chest, and femur. A significant reduction of the severity of injuries was found when the impact speed was reduced from 60 to 32 km/h. The accelerations experienced by the head and chest are found to be higher than safe levels for impact speeds of 48 and 60 km/h. The biomechanical limit for the right femur is exceeded at all three considered impact speeds. Neck injuries are also a concern, with the predicted tension values and neck bending extent being higher than the biomechanical limit for the 60 km/h impact speed. In light of these results, it is suggested that the design of guardrails should be reviewed with a focus on the safety of motorcyclists.

Cervical spine injuries sustained by motorcyclists in road crashes in Malaysia

Abstract This study looks at cervical spine injuries sustained by motorcyclists in motorcycle road crashes. The motorcyclist is relatively more exposed to road hazards compared to the protected car passenger. They are therefore more prone to injury than those traveling in any other form of transportation. The motorcycle is relatively less stable and accords little protection to passengers in road crashes compared to a four-wheeled vehicle. The cause of injury and injury mechanisms are more uncertain for a motorcyclist compared to a car driver. The objective of the present study is to correlate the motorcycle crash mode to the cervical injury sustained by motorcyclists in real-world scenes. Motorcyclists with cervical injuries admitted to the hospitals were selected for investigation. The types of injuries sustained were acquired from medical reports. Information on the crash scene and crash mode was obtained from police reports and interview sessions arranged with the motorcyclists involved in the crash. Generally, a high count was noted for injuries to the lower cervical vertebrae, especially at vertebrae C5, intervertebral C5-C6, and vertebrae C6. The upper cervical spine was observed to have a high frequency of injury at C2, especially the odontoid process. Statistical analysis reveals that the vehicle crash mode is significant in determining the cervical injury mechanism sustained by motorcyclists (p < 0.05), and thus basic injury types sustained. Neck flexion and extension movements are the most frequent neck injury mechanisms, especially in frontal and rear end impacted motorcycles. Burst fractures were commonly observed in frontal impacts, while side impact and skidding motorcyclists were found to have a high frequency of uncinate process fractures, a result of neck lateral flexion. At the end of the study, a logistic regression model was developed. The model is simple and may be referred by paramedics in making any prompt prediction related to neck injury of motorcyclist due to road crash.

Development of High Fidelity Finite Element Model of Motorcycle Telescopic Front Fork

This paper describes the development of a fully deformable finite element model of an upright telescopic motorcycle front fork in LS-DYNA environment. The modelling for each of the key components, overall assemblage, and contact interactions involved were presented. Comprehensive validation was performed by comparing the reaction forces in a quasi-static test performed on a universal testing machine with customised fixture, which was specially designed to impose compressive and bending load simultaneously on the fork unit throughout the process. The behaviour of the fork under such loading conditions was studied and explained. Significant localised deformations observed on the components were also identified and compared. The results from the simulations were found to be well agreed to that of the physical testing, with closely matching profile of the reaction forces and a deviation of 1.4 % based on the work done to deform the fork. Major considerations for establishing the full model were concluded and recommendations were suggested for improvement. (Received in September 2015, accepted in March 2016. This paper was with the authors 2 months for 2 revisions.)

Single Input Multi Output Adaptive Network Based Fuzzy Inference System for Machinability Data Selection in Turning Operations

The selection of machining parameters needs to be automated, according to its important role in machining process. This paper proposes a method for cutting parameters selection by fuzzy inference system generated using fuzzy subtractive clustering method (FSCM) and trained using an adaptive network based fuzzy inference system (ANFIS). The desired surface roughness (Ra) was entered into the first step as a reference value for three fuzzy inference system (FIS). Each system determine the corresponding cutting parameters such as (cutting speed, feed rate, and depth of cut). The interaction between these cutting parameters were examined using new sets of FIS models generated and trained for verification purpose. A new surface roughness value was determined using the cutting parameters resulted from the first steps and fed back to the comparison unit and was compared with the desired surface roughness and the optimal cutting parameters ( which give the minimum difference between the actual and predicted surface roughness were find out). In this way, single input multi output ANFIS architecture presented which can identify the cutting parameters accurately once the desired surface roughness is entered to the system. The test results showed that the proposed model can be used successfully for machinability data selection and surface roughness prediction as well.

Empirical model for impact response of motorcycle front spoked wheel-tyre assembly

Abstract An experimental study on the response of the motorcycle front wheel-tyre assembly in a frontal impact was conducted. A topological approach was employed whereby the post-impact projected deformation area of the wheel was selected as the response variable. Design factors included in the design of experiment were impact speed (S), impact mass (M), inflation pressure level of the tyre (P), contact geometry of the striker (G), and the offset distance of the impact location from the axle (D). A 2v5-1 fractional factorial design with four replications was applied. Statistical software, Minitab version 13, was employed in the experimental design and data analysis. The impact tests were conducted using the in-house developed pendulum impact test rig. A factorial analysis was performed to identify the significant factors influencing the responses of the wheel-tyre assembly. It was found that the influential effects for the response, excluding the torn-off cases, are the main effects S, M, P, and D, and interaction effects SM and PG. On the other hand, for the response including the torn-off cases, the main effects are the same but the interaction effects are slightly different, namely SM, MD, MG, and PG. These factors were then incorporated in the establishment of the empirical models for predicting the impact response of the wheel-tyre assembly. Regression analysis was also carried out to evaluate the yielded empirical models. Curves demonstrating the behaviour of the wheel under various impact conditions investigated were generated based on the empirical models. A comparison was also made with the findings where maximum residual crush was the response variable.

Experimental study on energy absorption characteristics of motorcycle front wheel—tyre assembly in frontal impact

Abstract This article presents a study on the frontal impact properties of the motorcycle front wheel—tyre assembly using squared change of velocity and dissipated impact energy as response variables. The laboratory-scaled impact tests were performed on the wheel—tyre assemblies using pendulum impact test apparatus according to a 25−1 V fractional factorial design with four replicates. Five parameters that are included in the experiment were impact speed (S), impact mass (M), tyre inflation pressure level (P), contact geometry of striker (G) and offset distance of impact location from axle (D). The test specimen used in the study was a spoked wheel of size 1.40 × 17. Minitab has been employed to support the entire experimental process. The collected experimental data were organized, and factorial analysis was performed. The significant factors influencing the impact responses of the wheel—tyre assembly were identified, which are S, M, P, D, SM and SD. The associated empirical models were then established and presented, followed by the factorial plots for the respective significant factors. The curves demonstrating the impact response of the wheel—tyre assembly under various impact conditions were generated from the developed models to illustrate the impact response of the wheel—tyre assembly under various impact conditions within the experimental region. Comparison was made to the values of dissipated energy predicted by the developed model and the values of impact energy from fundamental kinetic energy equation, and it was found that the model is consistent with the physical condition within the experimental region.