Automotive windshield — pedestrian head impact: Energy absorption capability of interlayer material

Abstract

During accident, the interlayer of windshield plays an important role in the crash safety of automotive and protection of pedestrian or passenger. The understanding of its energy absorption capability is of fundamental importance. Conventional interlayer material of automotive windshield is made by Polyvinyl butyral (PVB). Recently, a new candidate of high-performance nanoporous energy absorption system (NEAS) has been suggested as a candidate for crashworthiness. For the model problem of pedestrian head impact with windshield, we compare the energy absorption capabilities of PVB and NEAS interlayers, in terms of the contact force, acceleration, velocity, head injury criteria, and energy absorption ratio, among which results obtained from PVB interlayers are validated by literature references. The impact speed is obtained from virtual test field in PC-CRASH, and the impact simulations are carried out using explicit finite element simulations. Both the accident speed and interlayer thickness are varied to explore their effects. The explicit relationships established among the energy absorption capabilities, impact speed, and interlayer material/thickness, are useful for safety evaluation as well as automotive design. It is shown that the NEAS interlayer may absorb more energy than PVB interlayer and it may be a competitive candidate for windshield interlayer.

Experimental investigation on the radial and circular crack propagation of PVB laminated glass subject to dynamic out-of-plane loading

“…This is expected since the glass sheet with thicker PVB layer would absorb more impact energy via molecule vibration and friction by the interlayer as polymer-like material, verified by Ref. [45]. As the Rayleigh wave velocity c R % 3370 m/s [46], which is sufficiently high for the initiation velocity v 0 .…”

“…Martinez et al [44] reported that the capability for transmitting the impact energy depends on the thickness and type of the adhesive used. Therefore, the variation in PVB thickness will have a great effect on delaying the passage of the elastic wave into the backing glass layer and reducing the amplitude and the wavelength of wave through internal friction [45], which results in reducing the maximum radial crack speed as show in Fig. 9.…”

Energy absorption ability of buckyball C720 at low impact speed: a numerical study based on molecular dynamics

“…In particular, effective absorption of mechanical energy at low-impact speed, i.e., below 100 m/s is of great interest [5,6]. As one of the major branches of fullerene family, the carbon nanotube (CNT) has demonstrated an outstanding mechanical energy dissipation ability through water-filled CNT [7], CNT forest and bundle [7], CNT/epoxy nanocomposites [8], CNT immersed in nonaqueous liquid [9], intercalating vertical alignment with aligned existing layered compounds [10], and sponge-like material containing self-assembled interconnected CNT skeletons [11], among others.…”

Finite element based improvement of a light truck design to optimize crashworthiness

“…The crashworthiness of optimum designs with conventional steel and advanced high-strength steel were compared using the full vehicle analysis. Xu et al (2011) compared the energy absorbing abilities of high-performance nanoporous energy absorption system (NEAS) interlayer and polyvinyl butyral interlayer for windshield by conducting the simulations of windshield and pedestrian head impact. They concluded that NEAS interlayer may absorb more energy than PVB interlayer.…”