The article discusses the causes of the destruction of triplex car windshields related to the conditions of their installation, operation, as well as criminal hacking. A set of signs has been identified that allows for forensic diagnostics of the cause of the destruction of wind glazing in terms of shape, size of cracks and the pattern of their distribution over the surface. The most common cause of cracks on windshields is the impact of a flying stone. At an impact energy of up to 0.5-0.6 J, a chip or "asterisk" of short radial cracks forms on the outer layer of glass, at an energy of the order of 18-20 J, a grid of radial and concentric cracks resembling a spider web is formed on both layers of glass, and at an energy of 88-90 J and above, through punching of a triplex with a rupture of the gluing polyvinyl butyral layer. The second most important reason for the destruction of windscreen glazing is the presence of defects in the form of microcracks on its edge. When the glazing is destroyed from an edge defect during installation and operation, a characteristic fan of cracks appears, radiating from the point of damage. The third reason for cracking windshields is the destruction from temperature changes (thermal shock). In the presence of edge defects, the formation of cracks is possible already at a temperature gradient of 40 °C or even less. Characteristic signs of thermal shock destruction: the sinuous shape of cracks in the absence of their branching, the absence of a visible center of destruction, the mirror surface of the glass fracture. When using a gas burner or welding machine, a characteristic sign of criminal hacking is the bubbling of the bonding PVB layer in the zone of high-temperature exposure. The results of this work can be used in the production of forensic examinations of triplex windshields.
TRIPLEX AUTOMOTIVE GLASS, CAUSES OF DESTRUCTION, FORENSIC DIAGNOSTICS, DESTRUCTION FROM MECHANICAL IMPACT, BULLET DAMAGE, DESTRUCTION FROM INSTALLATION AND RESIDUAL STRESSES, DESTRUCTION FROM THERMAL SHOCK (TEMPERATURE DIFFERENCE OVER THE SURFACE)
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