An oil pump was fabricated with a transparent cover made of acryl resin in order to observe the inside of the pump. The images of cavitation in that pump were taken with a high speed camera. As a result, the behavior of cavitation from generating to collapse was revealed and the site of cavitation collapsed was agreed with the site of erosion occurred． The timing of collapse and the influence of flow were observed and it was possible to describe the process leading to erosion as a trochoid oil pump.

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In the present study, unsteady vehicle aerodynamics caused not by a periodic condition but by an intermittent disturbance has been investigated, especially focusing on the aerodynamic drag. Aerodynamics of simplified vehicle models, which had different geometry only in the rear-end corner, were measured in a wind tunnel with a transition of aerodynamic yaw angle. From the measurement results, relationship between unsteady aerodynamics and aerodynamic phenomena has been investigated. A model with the rounded corner shape showed hysteresis on the aerodynamic force. Transitional phenomenon of flow separation on the rear-end corner was considered as a cause of the hysteresis.

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Electric vehicles (EV) and Fuel cell vehicles (FCV) can use not only transportation equipment but also leveling of renewable energy generated fluctuations. In this paper, some new energy systems which are combined with photovoltaic power generator (PV), EV, heat pump (HP) water heater and hydrogen have been studied. As the concept of the systems, PV power is stored by electricity, thermal energy as hot water and hydrogen as fuel. Electricity charges EV battery and converts into thermal energy by HP. In addition, hydrogen is produced by using electricity. The advantages and disadvantages of the new systems were compared.

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We focused on the emission test method for the heavy-duty diesel vehicle. The emission test method of JE05 mode is evaluated for the heavy-duty diesel vehicle of Japanese 2005 regulation, and WHDC mode is used for 2016 years. In this report, the emission test method in the future was studied. We focused on the behavior of the shift change for the heavy-duty diesel vehicle mounted the eco-friendly technology. The emission characteristic driving at JE05 mode and WHDC mode for the conventional engine test and the virtual vehicles test was investigated. In particular, we clarified the problems of the shift behavior for the conventional emission test method. Next, we modified the engine driving pattern (engine speed and torque) to which the concept of the shift time applied.

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This research was aimed at preventing fracture of spot welds in Ultra High Strength Steel. The LTS test which is the joint test of peeling mode was used for the joint model. The effect of joint shape, sheet thickness and material strength on internal stress of nugget was investigated by experiment and numerical analysis. It was found that the stress value and distribution in the nugget changed depending on influence factors, and even if the nugget diameters were the same, it led to the change of joint strength.

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Loaded condition of spot weld zone was investigated by CAE when ultra-high-strength steel frames had high-speed 3 point bending deformation or torsional deformation to find some reasons of spot weld fracture of the frames. The result showed the condition depended on the deformed conditon. Additionaly, some appropriate joing methods were proposed to avoid the spot weld fracture based on the result. Concretely, under bending deformation mode, the method is expansion of the joining area at bending area and continuous joing such as line laser or short pitched spot weld around the bending area, under torsional deformation, both the expansion and continuous joing were useful. The validation of the proposal was confirmed by CAE and experiment of high-speed 3 point bending test and torsional test.

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Improvements of both crash performance and light weight are required in automobile structural members. In order to expand the application of ultra high strength steels to automobile members, it is important to improve the reliability of spot welded joints. In this study, the structure around the welded flange was examined for the purpose of reducing the stress of the spot welded joints. As a result, it is shown that the stress of the spot welded joints can be reduced by suppressing the deformation of the flange. In addition, the crash performance was improved due to the structural change of flange.

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This paper describes 4-point bending fatigue properties of vacuum carburized SCM415 in biodiesel fuel with water. To evaluate fatigue properties, fatigue strength evaluation method in fuel was newly established. The fatigue limit was 388 MPa which exhibits no difference from that in air. However, in short life region, the fatigue strength was lower than that in air. Intergranular fracture was observed at the fracture origin and its area tended to increase with increasing the number of cycles to failure. It was suggested that the strength reduction was caused by some influence of biodiesel fuel on the grain boundary.

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Since a standard spot welding condition sets target of diameter of nugget to 5√𝑡, the effect of nugget diameter on fatigue strength was included into the S-N curves of spot-welded joints with various sheet thickness. By analyzing the sensitivity of the tensile shear joints and the shear torsion joints with the nugget diameter 5√𝑡, the effects of sheet thickness and nugget diameter on fatigue strength were 7 to 3 for tensile shear and about 4 to 6 for shear torsion. The analyzed results for tensile shear agreed well with the fatigue test results.

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To adopt aluminum alloy in structure, it is important to develop most suitable joining technology. This paper describes effect of factors to fatigue strength in aluminum line laser welding with L-type joint. In the range of this study, gap between sheets, laser power and blow hole have effectiveness to fatigue strength , so those are important factors to fatigue strength.

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TRIP（TRansformation-Induced Plasticity） steels has excellent combination of strength and ductility due to the higher strain hardening properties. There are many researches on the deformation behavior and ductility of TRIP steels by tensile tests. However, the characteristics in a biaxial deformation which is the main body in actual press forming are not well known. For the application of the TRIP high strength steels to automotive structures, it is necessary to understand the forming behavior in various deformation modes, including plane stress and biaxial mode. In this study, forming limit diagram of 1180MPa grade TRIP steels are investigated with comparison of Dual-Phase steels of 590MPa and 1180MPa grade. As a result, it showed high dispensability of strain in all deformation modes and showed a stretch formability was equivalent to that of 590 MPa grade steel.

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TRIP (Transformation-Induced Plasticity) steels has excellent combination of strength and ductility due to the higher strain hardening properties. There are many fundamental and scientific researches on the deformation behavior and ductility of TRIP steels. As a practical performance of automotive parts， it is necessary to understand effect of strain-rate on the deformation behavior in order to improve the crashworthiness of body structure by using the high strength steels. In high strain-rate deformation， the temperature at the deformed potion could be increased by plastic working. So it is important to investigate effects of both strain-rate and temperature on material properties in deformation on the TRIP steels. In this study， strain-rate sensitivity of 1180MPa TRIP is investigated focusing on the temperature effect in high strain-rate. As the results， the interaction of strain-rate and temperature effects shows the important role for the high-speed deformation for the TRIP steels.

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Effect of graphite shape and matrix on fatigue strength characteristic of cast iron was studied. According to result of fatigue test in gray cast irons, effect of difference in matrix on fatigue strength was not significantly observed. Therefore, shape and size of graphite might be more dominant on the fatigue strength. Fatigue strength was well predicted by threshold stress intensity factor range and the maximum graphite size by assuming semi-circular crack in gray and spheroidal cast irons. In case of vermicular cast iron, stress shielding effect due to crack branching should be taken into account to predict the fatigue limit.

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This paper presents multiple object motion prediction using Deep Convolutional Neural Network (DCNN). Specifically our approach generates a potential map from the location data of multiple objects, and the DCNN learns to predict the future potential from the previous time frame. Advantages of this model are enabling the behavior prediction without using tracking by acquiring each object’s successive state. In addition, it was confirmed in our experiment that our model enables the multiple object detection at about 6 msec. per frame using GeForce GTX TITAN X of NVIDIA’s GPU.

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