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Anybody knows that contamination in oil is always harmful to hydraulic and lubricating systems. Contaminants inevitably exist in the oils of hydraulic and lubrication systems and cause tribological problems. In order to prevent such tribological problems due to contaminants, various oil cleaners have been developed and applied to hydraulic and lubricating systems. They have greatly contributed to improving the reliability of the systems. Since sophisticated hydraulic systems with proportional valves or servo valves, which are sensitive to oil contamination, became popular, fine filters like 3 micron or 1 micron are additionally used. However contamination problems have been revived. The authors have investigated the causes of hydraulic and lubricating problems and found that polymerized oil oxidation products were as harmful as solid particles. They are of molecular size and cannot be removed by mechanical filtration.

The goal of the present study was to develop a new legform impactor that accurately represents both the impact force (i.e., force between the leg and impacting mass)and leg kinematics in lateral impacts simulating car-pedestrian accidents. In its development we utilized the knee joint of the pedestrian dummy called Polar-2 (HONDA R&D) in which the cruciate and collateral ligaments are represented by means of springs and cables, the geometry of the femoral condyles is simplified using ellipsoidal surfaces, and the tibial meniscus is represented by an elastomeric pad. The impactor was evaluated by comparing its responses with published experimental results obtained using postmortem human subjects (PMHS). The evaluation was done under two conditions: 1)impact point near the ankle area (bending tests),and 2)impact point 84 mm below the knee joint center (shearing tests). Two impact speeds were used: 5.56 m/s and 11.11 m/s.

The objective of this research is to clarify the significant factors causing AIS 2+ femur or pelvis pedestrian injury, and to understand whether the current EEVC upper legform test reflects real world pedestrian accidents. An in-depth case study was conducted using the selected 82 pedestrian accident cases from 1987 to 1997 in the data base of Japan Automobile Research Institute (JARI) and Institute for Traffic Accident Research and Data Analysis (ITARDA). The results indicate the significant factors were the bonnet leading edge height, the vehicle registration year and the pedestrian age. The bumper lead was not a significant factor. However, the test condition of the EEVC upper legform test depends on the bumper lead and the bonnet leading edge height. The current test condition of the EEVC upper legform test should be reconsidered excluding the bumper lead.

Improvements for pedestrian head protection in a car-pedestrian accident have been discussed in several countries. Test methods for evaluating head protection have been proposed, and most are sub-systems using rigid headforms with or without headskin. In those tests, HIC is used as a criterion for head protection. This paper discusses the test conditions and requirements of the headform impact test. The influence of different test conditions and their importance on head impact test requirements, were verified. The primary items cited are as follows: (1) The results of the rigid headform were similar to that of the human cadaver skull in cases without skull fractures. Consequently, the rigid headform can be used for the impactor simulating a condition without skull fracture. (2) In the cases of HIC≤1000, the force-deformation curves of the hoodtops showed similar characteristics with maximum dynamic deformations over 60mm. (3) Impactor mass affected the maximum acceleration and HIC.