Papers by Keyword: Windshield

Abstract: The maximum vapor fraction in the air decreases with the temperature falling. For the air which has the high humidity, the redundant vapor will condense into fog or freeze into ice if the moist air attained a new saturation in a lower temperature. The buses running in the north cold areas usually face this problem in winter. According to the theory of jet impingement heat transfer, this thesis analyzed the influences of angle between the windshield and impinging jets and also the distance between vents and dashboard edge on defrosting by a simplified bus model. It also put forward some suggestions about defrosting on buses.

Abstract: The knowledge and principles of air conditioning as well as numerical analyses and experiments are applied to obtain the various defog guides depending on extreme wet-conditions and the various outside air temperatures in all seasons. The defog guides can be listed as a leaflet to let the drivers know how to operate their air-conditioning control panel properly to defog the windshield with suitable air to obtain the safe and comfortable driving.

Abstract: The defrosting is very important in vehicle. In the paper, some improved proposals to the lack performance of the vehicle windshield defrosting would be discussed by using computational fluid dynamic (CFD) numerical simulation analysis and experiment to validate the improved proposal. The improved proposal including change the angle of the grill of wind outlet, and add grill on the left and right side. The discrepancy of the two methods is in 5%, which is acceptable. By the improved proposal that the windshield defrosting area is increased and also the requirements is satisfied.

Abstract: The analysis of windshield against bird strike is necessary for reducing the disastrous consequences. The flat windshield which involves two pieces of glass together with a polyurethane interlayer is often used in the aircraft. The mechanical property of the polyurethane interlayer is an important factor of affecting the response of windshield against bird strike. This effect is investigated in this work by simulating the bird impacting the flat windshields with the polyurethane of different elastic modulus. The bird is modeled with SPH method. The calculation results indicate that the elastic modulus of polyurethane affect the response of windshields in many points. For the elastic modulus of 5 MPa, the thickness of polyurethane interlayer is compressed by 16% during the striking. The compressive effects decrease the contact force and the displacement of windshield to some extent. Especially, the major principle stresses in the inner and outer glass are decreased by the compressive effects significantly. It is found that the major principle stresses in the outer glass are 103 MPa lower than those of the case with the elastic modulus of 600 MPa. The relatively small stress in the glass means that the windshield can afford more serious impact and has the better impact resistance.

Abstract: Finite element simulations are widely used in the analysis of bird strike events in the literatures. While the shapes of the artificial birds used in the simulations are not indentical. In order to investigate the effects of artificial bird shapes on the response of laminated aircraft windshield, the often used shapes including hemispherical-ended cylinder, straight-ended cylinder and ellipsoid are modeled in this work. The striking velocity is 80.6 m/s and the SPH method is adopted. Based on the calculation results, the impact force, dissipated energy and major principle stress in the glass are analyzed. The analysis shows that the initial contact area would affect the values of these results. The shapes and aspect ratios affect the results through the initial contact area.

Abstract: A method based on the 3D laser scanning is proposed for obtaining and analyzing the windshield's deformation in vehicle-pedestrian accident. With an actual traffic accident of vehicle-pedestrian collision taken for example, point cloud data of windshield’s deformation is scanned by EXAScan 3D laser scanner and the deformed 3D NURBS surface is obtained after fitting process. Based on the discussion about characteristics of curved surface of the vehicle’s front windshield and the principle of continuous curvature, this paper conducts a surface fitting with cubic non-uniform spline according to geometric information of grid surface around the deformation zone, and obtains the pre-deformed surface of windshield by sampling with spline curve. Compared with the pre-deformed surface of vehicle’s windshield, the maximum deformation depth is 48.509mm and its area is 0.3816m² on the right side, while the maximum deformation depth is 36.341mm and its area is 0.2529m² on the left side. The application results in actual traffic accident show that this method can be used to obtain 3D deformation information of overall impact area, which provide a new method for accurately inspecting the windshield’s deformation in vehicle-pedestrian accident. This method also provides a new research idea for quantitative saving the evidence in permanent, and it also has a great value in accident analysis and reconstruction.

Abstract: In the paper, a new type of high-frequency microwave heating method for windshield forming process was investigated. In order to obtain the effects of forming process parameters and windshield properties on the forming qualities of windshield, the distributions of electromagnetic energy and temperature were simulated by coupling electromagnetic analysis with multi-physics analysis. Moreover, the influence of different microwave input frequencies on electromagnetic energy and temperature distributions was analyzed. The results show that a travelling-standing wave distribution of electromagnetic energy is formed within windshield. And the temperature distribution and heating time are determined by combined influences of windshield properties and microwave frequency. And the necessary temperature distribution can be realized by electing appropriate microwave frequency.

Abstract: Nowadays the production of mold seriously restricts the manufacture of products as well as the development of new products, it has become an urgent problem to be solved. The paper mainly discussed the fuzzy neural network model and learning algorithm, and utilized expert evaluating system to acquire the training and test samples. Moreover, it established the related mapping model for fuzzy neural network to evaluate the assemblability of mold, so as to improve the productivity of mold. By adopting two different fuzzy neural networks to contrast and evaluate the assemblability evaluation system of the parts of windshield mold, it was concluded that the improved fuzzy neural network model had advantage over the conventional one. Finally, the satisfactory results of assemblability evaluation system of windshield mold had been achieved by coming with examples to carry out error analysis of the assemblability evaluation system.

Abstract: This paper is focused on the development of an effective numerical method to simulate bird-impact aircraft windshield events. A new Smooth Particle Hydrodynamics (SPH) which has been incorporated as a solver option into the explicit finite element program PAM-CRASH was used to model the bird. The deformation between the numerical results and the experimental results is in good agreement. Simulation results of a bird-impact process indicated that the SPH bird model is more suitable to model the break-up of the bird into particles. Failure of the windshield in the experiment was simulated, and the good agreement between the numerical and experiment indicates that the failure model established in the present paper is reasonable. Finally, the energy changes of the bird and the windshield were calculated.