Dynamic Response Of Hollow Tempered Laminated Glass Under Blast And Impact Loading

As a common building material,glass panels meet the dual functions of practicability and aesthetics.Therefore,they are widely covered on the outer walls of large buildings.However,the problem that follows is that once a major natural disaster or explosion occurs.As a typical brittle material,glass is easily broken,and high-speed flying fragments will cause unnecessary casualties and economic losses.Therefore,people attach great importance to the study of its mechanical properties.This paper used a combination of experiment and numerical simulation to study the dynamic response of hollow tempered laminated glass under explosion and impact loads.The specific content includes:(1)The dynamic response of hollow tempered laminated glass under explosive load was studied by using the ballistic impact pendulum system and the fixed glass bearing device.The results analyzed the overall deformation characteristics and crack laws of the hollow tempered laminated glass,and discussed in detail the influence of the thickness of the PVB glue layer,the thickness of the intermediate air layer,the amount of explosives and the explosion distance on the overall anti-explosive performance of the hollow tempered laminated glass.(2)The finite element software LS-DYNA was used to simulate the dynamic response process of the explosion shock wave acting on the hollow tempered laminated glass.The simulation used the LOAD-BLAST algorithm,and used the element deletion method to reflect the law of crack propagation.The effect of explosive quality and blasting distance on the damage mechanism of hollow tempered laminated glass was analyzed,and the crack propagation law and failure mode of hollow tempered laminated glass under different explosion environments were discussed.(3)A rigid drop hammer was used to conduct a drop hammer impact test on a hollow tempered laminated glass.The impact test was divided into 3types.The experimental results described the crack morphology of the hollow tempered laminated glass when it was broken,and evaluated the effect from the peak impact load,energy absorption rate and strain.The relevant research results of hollow tempered laminated glass show that:(1)While maintaining the thickness of the intermediate air layer,with the increase of the thickness of PVB glue layer,the overall structural strength of the sample is increased;On the premise of keeping the same thickness of the PVB glue layer,as the thickness of the intermediate air layer increases,the overall stability of the structure decreases and the anti-knock performance gradually weakens.Changing the amount of explosives and the explosion distance also has a great impact on the dynamic response of the hollow tempered laminated glass.Keep the explosion distance constant,as the amount of explosives increases,the damage of the hollow tempered laminated glass gradually increases.Keep the amount of explosives constant,as the explosion distance increases,the central damage area of the outer glass of the sample becomes smaller,and the damage degree of the hollow tempered laminated glass gradually decreases.(2)The results of the numerical simulation are consistent with the results of the explosion experiment.With the increase of the explosive amount and the decrease of the explosion distance,the density of radial cracks and circumferential cracks on the surface of the hollow tempered laminated glass gradually increases,the degree of damage to the structure is gradually increasing.(3)For hollow tempered laminated glass,when the impact layer glass and inner layer glass are thicker,the overall strength of the structure is greater,and the impact load and impact energy required for breaking are greater,and the corresponding impact resistance is stronger;Comparing plan 1 and plan 2,without considering whether the structure is symmetrical and the total thickness is the same,the impact resistance of the hollow tempered laminated glass increases with the increase of the thickness of the impact layer glass;Comparing plan 2 and plan 3,it is found that even for the same size glass sheet and PVB glue layer,the different combination of the two materials will affect the overall performance of the hollow tempered laminated glass.The thicker the glass on both sides of the air layer,the stronger the impact resistance of the hollow tempered laminated glass.