Automobile Windscreens Research Articles

Dynamic substructuring for visco-elastic materials using a POD-based model reduction method: application to laminated panels

Dynamic substructuring is now a well established and powerful tool for engineers used to analyze the dynamic response of mechanical systems. The technique is particularly favored for the simulation of mechanical vibrations allowing different aspects to be studied. It consists in splitting the global structure into several substructures from which reduced models are built. In Finite Element software, these reduced models, also called superelements, are generally built using the concept of Component Mode Synthesis. Difficulties arise when structures made of frequency-dependent materials are considered since classical modal reduction algorithms are inapplicable as they are because of the frequency-dependence of the stiffness matrix. Based on the Balanced Truncation approach, a novel methodology for the construction of a superelement for the dynamic analysis of elastic structures made with viscoelastic materials is presented. The methodology takes advantage of the Golla-Hughes-McTavish rheological model (GHM) before reducing the system via the Balanced Proper Orthogonal Decomposition (BPOD). The coupling of the superelement with a host structure is achieved via the use of Lagrange multipliers. The reduced system takes the form of a constant matrix of very small size compared to the original FE model. The method is applied to laminated panels such as an automobile windscreen.

Optimal Mixture of Materials and Condition in Producing Flat Glasses for Automobile Windscreens in Nigeria

The selection of materials is an essential element for engineering designers. This study investigated the optimal mixture of materials and condition in producing flat glasses for automobile windscreens in Nigeria. To achieve this, 10 pairs of compositions of material mixtures and cullet (broken glasses) were used. The standard material mixture (80/20 wt. % of material mix/cullet) from the local industry was modified to have batches of up to 60/40 wt. % material mix/cullet. These material mixtures were used to produce flat glasses by adopting procedures of industrial float glass process of Pilkington Brothers in variable conditions of annealing temperature and time. The average density of each pair of flat glass was measured using water displacement method, and each pair was later laminated to produce a total of 10 automobile windscreens. The windscreens were subjected to 2.25kg drop ball impact test from a height of 4m at 900. The study revealed that the density of the flat glass produced was significantly (p< 0.01) related to squared composition (wt. %) of cullet (R2=97.65%). The highest and lowest densities of 2.23g/cm3 and 1.95g/cm3 were obtained at cullet inclusions of 40 wt. % and 20 wt. % respectively at constant annealing temperature (5500C) and time (60 min). The optimal batch obtained composed of 40 wt. % cullet inclusion, annealed at 5000C for 50 minutes. Increased cullet composition was found to reduce the melting temperature of the batch mixture and fractured characteristics of the windscreens produced. Employing this design in the windscreens manufacturing industry saves production cost, facilitates a competitive market, enhance the quality of windscreens, reduce emissions and curb environmental degradation.

Pothole and Wet Surface Detection Using Pretrained Models and ML Techniques

Abstract: Roads contribute significantly to the economy and serve as a transportation platform. Road potholes are a key source of worry in transportation infrastructure. The purpose of this research is to develop an Artificial Intelligence (AI) model for identifying potholes on asphalt pavement surfaces. Image processing techniques from pretrained models such as efficientnet, resnet50, mobilenet and ML models such as random forest, decision tree, SVC, SVM. Several studies have advocated employing computer vision techniques, including as image processing and object identification algorithms, to automate pothole detection. It is important to digitize the pothole identification process with acceptable accuracy and speed, as well as to deploy the procedure conveniently and affordably. Initially, a smartphone placed on the automobile windscreen captures many photographs of potholes. Later, by downloading pothole photographs from the internet, we expanded the amount and variety of our collection (2400 images with over 900 potholes). Second, to locate potholes in road photos, several object detection methods are used. To compare pothole detection performance, real-time Deep Learning algorithms in various setups are employed. Similarly Wet pavement decreases surface friction dramatically, increasing the likelihood of an accident. As a result, timely understanding of road surface condition is essential for safe driving. This research proposes a unique machine learning model pipeline for detecting pavement moisture based on live photos of highway scenes acquired via accessible to the public traffic cameras. We refined existing state-of-the-art feature extraction baseline models to capture background instance targets, such as pavement, sky, and vegetation, which are frequent in highway scenes, to simplify the learning job.

Transparent, self-cleaning, scratch resistance and environment friendly coatings for glass substrate and their potential applications in outdoor and automobile industry

In this research work six novel combinations of Hydroxy Ethyl Meth Acrylate based copolymers have been synthesized and commercial titania, after activation was added by adopting simple strategy to manufacture super-hydrophobic, cost effective, transparent, antifogging, self-cleaning and antimicrobial coating on the glass sheet which will be helpful for outdoor and automobile windscreen. The super-hydrophobic covering was set up by dip covering procedure and coated specimen have been characterized for Wetting behaviour, transparency and SEM analysis. Likewise, the dependability of the coating was evaluated at conditions comparable strengthening at higher temperatures (4–400 °C), illumination by UV spectrum at basic and acidic limits, Results revealed that developed material has good adhesion with glass and shows transparency more than 97%, and water contact edge (CA) of 135 ± 2°. Furthermore, the covering displays astounding self-cleaning property. All the outcomes demonstrated that such kind of coatings could be used many modern level applications on automobile wind screen and glass-windows in building and other glasses where protection from UV radiation, anti-fogging and cleaning is required. Such type of coating material can also be used to preserve architectural work leather and other decoration and artwork. The graphical representation is given in Fig. 1.

Facile microwave-assisted synthesis of Cr2O3 nanoparticles with high near-infrared reflection for roof-top cooling applications

Microwave-assisted solution synthesis was employed for the preparation of Cr2O3 nanoparticles using Cr(acac)3 and ethylene glycol. The optimum conditions for the completion of the reaction forming a green precipitate (yield-95%) were: irradiation for 40–60 min at 220 °C solution temperature. The as-prepared sample was barely crystalline; annealing in air at above 300 °C formed nanocrystalline Cr2O3, as shown by X-ray diffraction (XRD). High-resolution transmission electron microscopy (HRTEM) of the “700 °C sample” confirmed the well-crystallised Cr2O3 formation with ∼37 nm average size. The as-prepared powder (bluish-green) showed high near-infrared (NIR) reflectance, whereas the annealed samples showed bright-green reflectance, whose International Commission on Illumination L*a*b* (CIE L*a*b*) values shifted towards the green region. The higher Dq/B value (3.76), suggested that Cr3+ lies in a strong crystal field. Stainless steel blocks covered with the as-prepared (intermediate) material reduced heating under sunlight by 5 °C, indicating its suitability as an easily prepared tile coating for roof-top applications. The annealed samples are found suitable as an anti-dazzling coating for automobile windscreens and rear-view mirrors.

Impact of windscreen scatter on laser eye dazzle.

This study investigates the extent to which a windscreen affects the severity of laser eye dazzle (disability glare produced by a laser) experienced by a human observer. Windscreen scatter measurements were taken for a range of windscreens in a variety of conditions, showing that windscreen scatter is similar in magnitude to scatter from the human eye. Human subject experiments verified that obscuration angles caused by laser eye dazzle could be increased by the presence of a windscreen when comparing a dirty automobile windscreen to an eye-only condition with a 532-nm laser exposure. However, a light aircraft windscreen with lower scatter did not exhibit increased obscuration angles at 532 nm, and neither windscreen exhibited an increase at 635 nm. A theoretical analysis of laser eye dazzle, using measured windscreen scatter functions, has provided insight into the delicate interplay between scatter, transmission and the angular extent of dazzle. A model based on this analysis has been shown to be a useful tool to predict the impact of windscreens on laser eye dazzle, with the goal of informing future updates to the authors' laser eye dazzle safety framework.

Design of Feeding Mechanism of Armature Guide Ring Automatic Assembly Equipment Based on TRIZ Theory

Solved the problem of high efficient and stable feeding in the structure design of the armature guide ring automatic assembly equipment of the automobile windscreen wiper motor, and the design of feeding mechanism of armature guide ring automatic assembly equipment is designed by using the principle of conflict resolution in TRIZ innovative design theory. By analyzing the relationship between the function design requirements of the feeding mechanism and the 39 engineering parameters in the TRIZ, the contradiction matrix of the feeding mechanism is established, and the principle of the conflict resolution is analyzed and the corresponding principle solutions are found. The design scheme is evaluated according to the traditional design experience. The design scheme of the feeding mechanism of the armature guide ring automatic assembly equipment is determined.

An Approach Regarding Windshield Wiper Mechanism Design

This research presents the use of a computer oriented numerical approach in the characterization of a parallelogram mechanism used on automobile windscreen wipers. The aim is to perform a kinetostatic analysis for obtaining through numerical simulations the joint reaction forces for a parameterized mechanism. Based on a combination between classical methods and computer simulations using Multi-body System method, the friction forces between wipers blades and windshield will be evaluated. The obtained results add new contributions on automobile windshield wiper mechanism design and analysis.

Comparison of material structures and scratch strength of thin films of glass mirrors and automobile windscreens

Several types of European and Asian automobile windscreens coated with single and multilayer fixing fluxes and silver thin films were studied, and their material structures and their scratch properties were compared with glass mirrors' by the authors. The realized laboratory tests had shown very strong influences of cracks and bubbles in the microstructures of fixing thin film layers and silver coatings on scratch resistance, acoustic emission and micro-hardness of the coatings both on glass mirrors and automobile windscreens. To examine the material structure of flux thin film layers and silver coatings scanning electron microscopy (SEM) was used. The scratch resistance, acoustic emission, nucleation and propagation of cracks were studied by an optical digital mechanical scratch tester.

Finite element analysis of the dynamic behavior of a laminated windscreen with frequency dependent viscoelastic core

This paper presents numerical and experimental validation of results obtained by a shell finite element, which has been developed for modeling of the dynamic behavior of sandwich multilayered structures with a viscoelastic core. The proposed shell finite element is very easy to implement in existing finite element solvers, since it uses only the displacements as degrees of freedom at external faces and at inter-layer interfaces. The displacement field is linearly interpolated in the thickness direction of each layer, and analytical integration is made in the thickness direction in order to avoid meshing of each sandwich layer by solid elements. Only the two dimensional mid-surface of reference is meshed, facilitating the mesh generation task. A simplified modal approach using a real modal basis is also proposed to efficiently calculate the dynamic response of the sandwich structure. The proposed method reduces the memory size and computing time and takes into account the frequency-dependence of the polymer core mechanical properties. Results obtained by the proposed element in conjunction with the simplified modal method have been numerically and experimentally validated by comparison to results obtained by commercial software codes (MSC/NASTRAN and ESI/RAYON-VTM), and to measurements done on automobile windscreens.

Typical defects on automobile windscreens at the interfaces of silver coatings, copper filaments and glasses

Typical defects on automobile windscreens at the interfaces of silver coatings, copper filaments and glasses

The influence of automobile windscreen rake on effective light transmittance

The theoretical transmittances at the installation angle of the windscreens of the ten best-selling cars in the UK in 2008 are investigated. The data show that the ten most popular cars on the UK roads have a windscreen rake that reduces transmittance to a value close to or below that specified in International Standards for normal incidence. British and International Standards for windscreen transmittance should be revisited by the relevant authorities in the light of the high rake angles that have become widespread in recent years. The problem is worsened considerably by tinted windscreens having become the default option in many models. It is also suggested that there may be good reason for all spectacles supplied to drivers for low light level driving to be untinted and anti-reflection coated.

Automobile Windscreen Rake, Spectacle Lenses, and Effective Transmittance

To investigate the effect of windscreen rake angle on effective transmittance and the contribution of spectacle lenses to the total transmittance of the system. Theoretical analysis has been carried out using the Fresnel reflectance equations. Windscreen rake can reduce effective transmittance significantly at angles present on modern aerodynamic vehicles. Spectacle lenses reduce the total transmittance still further, often to below the minimum level permissible in current international standards for windscreens. Drivers should always be supplied antireflection-coated lenses where there is a chance of their spectacles being used for night-time driving, if current International standards for windscreen transmittance are to be met by the spectacle-windscreen combination. Windscreen rake angle should be accounted for both in the International Organization for Standardization transmittance standards and in roadside testing devices.

Automatic demisting control of automobile windscreen glass

Mist frequently forms on automobile windscreen glass in cold humid weather. The present paper describes the development of a control device for automatically demisting windscreen glass. Automatic demisting control is initiated when the surface temperature of the glass is lower than the dew point temperature at a given relative humidity and temperature of the cabin inside. It was decided to attach the sensors measuring surface temperature and humidity on the bottom right of the glass and on the back of the rear-view mirror respectively, based on the observation of experiments. The demisting control strategy was originally designed to increase blower speed, change mode, mix hot and cold air, and turn on/off the air conditioner as the mist formed increases. The automatic device was operated with the automatic temperature controller of a heating, ventilation, and air conditioning (HVAC) system and successfully demonstrated in a vehicle test in a cold chamber by following the designed control strategy.

Simulation of windscreen bending using viscoplastic formulation

Soda-lime glass material has been widely used for automobile windscreens. Two commercial finite element programs have been evaluated for simulation of the creep forming process using isotropic viscoplastic behavior assumption for soda-lime glass. This was done by selecting one of the programs and using it in connection with an optimization program for controlling the glass surface temperature, to examine the effect of considering thermal stresses and temperature variations along the surface of glass sheet for obtaining desired geometrical shape. The results show that the thermal stress effect must be considered for achieving more accurate simulation of glass creep forming process. Also simulation results show that not only the varied temperature procedure can be used in creep forming process but also it becomes possible to reduce the amount of variation by increasing the temperature. Utilizing the higher creep forming temperatures could lead to lower production time. The accuracy of simulation results have been evaluated by comparisons of the measured slope and thickness of creep formed glass sheets in the constant temperature procedure with similar simulation results.

A variational inequality formulation of an inverse elasticity problem

We present some systematic approaches to the mathematical formulation and numerical resolution of an optimal control problem in linear elasticity. The objective of the optimization is to match a desired displacement by controlling the Young's modulus so as to minimize a quadratic functional. Theoretical results are presented in the general framework of linear elastic theory which lead to a variational inequality. Also, we define and analyze a finite element approximation of the optimality system and a gradient method for the solution of the discrete variational inequality. Finally, numerical experiments for the simulation of a simplified model for the “sag bending process” in the manufacturing of automobile windscreens are discussed.

Windscreen Dirt and Surface Damage Effects*

It is reasonable to assume that the condition of the windscreen has something to do with the ability of a driver to see through it. One study implies that seeing ability is impaired by scratched windscreens, a second evaluates cleaning methods for improving the wettabllity of the glass surface to improve the ability to see through ft, a third evaluates water repellent materials for use on aircraft windscreens and a fourth concludes from three windscreens that surface damage reduces the perceptibility of objects on the roadway. (See text.) This study was designed: (a) to obtain a population sample of automobile windscreen surface damage and dirt accumulation, (b) to evaluate the ability to see through the dirt and surface damage in a static and dynamic driving situation, and (c) to evaluate the practicability of resurfacing automobile windscreens.

On the bending of architectural laminated glass

As a result of its numerous environmental qualities, laminated safety glass is being used to an increasing extent in the field of architectural glazing. Its use in the manufacture of aircraft and automobile windscreens is well established, and the impact resistance of such laminates has been extensively studied. However, little work appears to have been done on the response of architectural laminated glass to normal structural loading. In this context, an architectural laminate is defined as comprising two glass layers of arbitrary thickness together with an adhesive plastic interlayer. The aim of the present work is to provide an insight into the fundamental behaviour of architectural laminated glass in bending. To this end, theoretical and experimental studies have been made concerning the action of laminated glass beams in four-point bending. Closed-form expressions are derived for the interfacial shear traction and central deflexion, and relevant numerical values are given. Experimental results are also presented; these relate to a series of tests on small laminated glass beams subjected to both transient and sustained loading at various ambient temperatures. In general, the degree of coupling between the two glass layers is shown to be chiefly dependent upon the shear modulus of the interlayer, which in turn is found to be a function of both the ambient temperature and the duration of loading; in this connexion, basic data are given on interlayer shear stiffness which can be utilized in subsequent structural analyses of architectural laminates.