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The goal of this paper, is to establish a pedestrian’s head injury risk, when it impacts a vehicle’s windshield. Hence, three experimental tests were performed, on an experimental test bench. Therefore, we want to determine which area of the windscreen is the most „friendly” in case of car to pedestrian accidents.

The paper deals with a windshield wiper mechanism with two parallel rocker blades having a complex topological structure. In the first part of the paper, the mobility of the mechanism is analyzed by means of the simplest formula for planar linkages. Also, the topological structure consisting of adyad and a tetrad has been outlined. In the second part of the paper, a kinema-tic analysis of the multi-contour mechanism is performed, the angular displacements of the two rocker blades being obtained. In this regard the independent contour method has been used, the angular displacements of all kinematicelements of the mechanism being calculated. Moreover, the displacement systems have been derived in order to obtain the velocities and late-on the accelerations of the mechanism elements. Finally, the paper ends with the displaying of the kinematic charts of the mechanism elements of which those with themovement of the two parallel rocker blades are the most wanted. This is due to the requirement of maximization of the wiping surface which is a very important safety issue.

Collections of rolling colloids are shown to pinch off into motile clusters resembling droplets sliding down a windshield. These stable dynamic structures are formed through a fingering instability that relies on hydrodynamic interactions alone. Condensation of objects into stable clusters occurs naturally in equilibrium 1 and driven systems 2 , 3 , 4 , 5 . It is commonly held that potential interactions 6 , depletion forces 7 , or sensing 8 are the only mechanisms which can create long-lived compact structures. Here we show that persistent motile structures can form spontaneously from hydrodynamic interactions alone, with no sensing or potential interactions. We study this structure formation in a system of colloidal rollers suspended and translating above a floor, using both experiments and large-scale three-dimensional simulations. In this system, clusters originate from a previously unreported fingering instability, where fingers pinch off from an unstable front to form autonomous ‘critters’, whose size is selected by the height of the particles above the floor. These critters are a stable state of the system, move much faster than individual particles, and quickly respond to a changing drive. With speed and direction set by a rotating magnetic field, these active structures offer interesting possibilities for guided transport, flow generation, and mixing at the microscale.

Surveys in German nature reserves point to a dramatic decline in insect biomass. Key members of ecosystems may be slipping away. Entomologists call it the windshield phenomenon: Car windshields used to be covered in the spring and summer months with the remains of insects. Today, cars remain clean. Observations about splattered bugs don't count as scientific, of course, but remarkably few reliable data exist on the fate of these important species. Scientists have tracked alarming declines in domesticated honey bees, monarch butterflies, and lightning bugs. But few have paid attention to the moths, hover flies, beetles, and countless other insects that buzz and flitter through the warm months. Of the scant records that do exist, many come from amateur naturalists, whether butterfly collectors or bird watchers. Now, a new set of long-term data is coming to light, this time from a dedicated group of mostly amateur entomologists who have tracked insect abundance at hundreds of nature reserves across western Europe for more than 30 years. Over that time, the group, the Krefeld Entomological Society, has seen the expected ups and downs in the yearly insect catches. But in 2013 they spotted something alarming. When they returned to one of their earliest trapping sites from 1989, they found that the total mass of their catch had fallen by nearly 80%. Perhaps it was a particularly bad year, they thought, so they set up the traps again in 2014. The numbers were just as low. The group, which had carefully saved thousands of samples over 3 decades, did more direct comparisons. They found dramatic declines across more than a dozen other sites. Their observations raise questions about how widespread such losses are, and what might be the cause.

This paper studies a typical failure case of the windshield heating system for civil aircraft. Through system disassembly, fleet data statistics, and failure mechanism analysis, it reveals the systemic failure mechanism caused by the coupling effect of seal structure failure, water ingress, and electrochemical corrosion. The study shows that external water infiltration due to windshield seal failure, leading to corrosion in the junction box and forming short-circuit loops, is the key factor causing windshield heating failure. Based on the above analysis, recommendations were proposed to improve the windshield sealing process, optimize windshield design, and enhance windshield maintenance inspection and training standards, providing important references for preventing and improving windshield heating failure issues.

Purpose An understanding of the behavior of a new ACL graft in the femoral tunnel during knee motion and external loading can provide information pertinent to graft healing, tunnel enlargement, and graft failure. The purpose of the study was to measure the percentage of the tunnel filled by the graft and determine the amount and location of the graft–tunnel contact with knee motion and under external knee loads. Methods Single bundle anatomical ACL reconstruction was performed on six cadaveric knees. Specimens were positioned with a robotic testing system under: (1) passive flexion–extension, (2) 89-N anterior and posterior tibial loads, (3) 5-N m internal and external torques, and (4) 7-N m valgus moment. The knees were then dissected, repositioned by the robot and the geometry of the femoral tunnel and graft were digitized by laser scanning. The percentage of tunnel filled and the contact region between graft and tunnel at the femoral tunnel aperture were calculated. Results The graft occupies approximately 70% of the femoral tunnel aperture and anterior tibial loading tended to reduce this value. The graft contacted about 60% of the tunnel circumference and the location of the graft–tunnel contact changed significantly with knee flexion. Conclusion This study found that the graft tends to rotate around the tunnel circumference during knee flexion–extension and contract under knee loading. The “windshield–wiper” and “bungee cord” effect may contribute to femoral tunnel enlargement, affect graft healing, and lead to graft failure. There can be a considerable motion of the graft in the tunnel after surgery and appropriate rehabilitation time should be allowed for graft–tunnel healing to occur. To reduce graft motion, consideration should be given to interference screw fixation or a graft with bone blocks, which may allow an earlier return to activity.

The objective of the present study is to characterize a rain tunnel that is used for performance testing of aircraft windshield rain removal systems. The rain tunnel in the present study is an open jet wind tunnel with six full cone pressure swirl nozzles arranged at its outlet. Experiments are conducted with water at room temperature as the working medium. The influence of total water supply flow rate and air velocity on the blowing-rain intensity and uniformity is studied. The total water supply flow rate varies from 0.57 m 3 /h to 1.03 m 3 /h, while the pressure at the inlet of the nozzle ranges from 1.44 bar to 6.52 bar. The air velocity of 30 m/s, 40 m/s, and 50 m/s is studied. A special test setup has been designed for measurements of the blowing-rain intensity and uniformity. Experimental results indicate that the blowing-rain intensity and uniformity both increase with the increasing total water supply flow rate and decrease with the increasing air velocity.

Strong excitation effect on the outer windshield structure induced by unsteady airflow around the connection between carriages has been normally detected in full-scale tests, which leads to violent vibration of the outer windshields due to strong nonlinear fluid–structure interaction (FSI) between the flow field and the structure. Previous studies normally treat the outer windshield structure as rigid bodies, and the coupling effect between unsteady flow and elastic structure has not been considered. The purpose of this study is to establish a two-way iterative FSI model based on a full-scale test, obtain the flow field characteristics around the outer windshields through FSI simulation, and analyze their vibration mechanism and characteristics. The results show that the iterative computing of two-way coupling has good applicability for the analysis of the vibration of the outer windshields of a high-speed train (HST). The relative deviation of the surface pressure of the outer windshield between the test and simulation is 4.3%, and the relative deviation of the main frequency of pressure change is 1.9%. Under the action of aerodynamic loading, two opposite U-section rubber capsules produce dislocation deformation movement, which produces bending deformation, and the deformation vibration frequency is close to the first-order natural frequency of the structure. Then, under the coupling action of aerodynamic, elastic, and inertial forces, the vibration mode close to the high-order natural frequency of the outer windshield structure is excited, and the displacement phase of the outer windshield presents prominent periodicity. This study can provide a reference for the study of aeroelastic problems of the external structure of HSTs.

Driving an automated vehicle requires a clear understanding of its automation capabilities and resulting duties on the driver’s side. This is true across all levels of automation but especially so on SAE levels 3 and below, where the driver has an active driving task performance and/or monitoring role. If the automation capabilities and a driver’s understanding of them do not match, misuse can occur, resulting in decreased safety. In this paper, we present the results from a simulator study that investigated driving mode awareness support via ambient lights across automation levels 0, 2, and 3. We found lights in the steering wheel to be useful for momentary and lights below the windshield for permanent indication of automation-relevant information, whereas lights in the footwell showed to have little to no positive effects on driving mode awareness.

With the frequent occurrence of bird strikes, minimizing the impact damage effect of birdstrike on flight always is the goal of airworthiness certification. As a large windward component in front of the aircraft, the windshield, and frame have more probability to be suffered from birdstrike. This paper introduces the common connection forms of the windshield frame structure of civil aircraft, and through the interpretation of the airworthiness requirements related to windshield in CCAR-25, puts forward the process and method of compliance verification of windshield frame birdstrike. Based on the SPH method, the dynamic analysis of bird impact on windshield window frame is carried out, the test is carried out to verify that the analysis method is reasonable and conservative, and the results show that the bird impact performance of the windshield frame structure meets the airworthiness requirements.