Numerical study on the structural response of blast-loaded thin aluminium and steel plates

Abstract

The inelastic response of thin aluminium and steel plates subjected to airblast loading is studied numerically and validated against experimental data. Special focus is placed on the influence of elastic effects and negative phase on the structural response. The blast loading was varied by detonating spherical charges of plastic explosives at various stand-off distances relative to the centre point of the plates. The numerical results obtained with the finite element code EUROPLEXUS were in good agreement with the experiments and predicted the entire range of structural response from complete tearing at the supports to a more counter-intuitive behaviour (CIB) where the final configuration of the plate was in the opposite direction to the incident blast wave due to reversed snap buckling (RSB). RSB attracted special attention since this is an unstable configuration sensitive to small changes in the loading and in structural characteristics. The negative phase of the blast pressure is usually neglected in blast-resistant design. However, the numerical simulations showed that the negative overpressure dominated the structural response and led to RSB at some loading and structural conditions. Two distinctive types of CIB were identified and both were found to depend on the timing and magnitude of the peak negative overpressure relative to the dynamic response of the plates. The study also revealed that CIB may occur in thin plates when the negative impulse is of the same order of magnitude as the positive impulse. The partial and complete failure along the boundaries observed in some of the tests was also successfully recreated in the simulations by using an energy-based failure criterion and element erosion.

Testing and modelling of annealed float glass under quasi-static and dynamic loading

“…Typical expressions used to describe the negative phase of the blast wave can be found in Aune et al [22]. The Friedlander equation will be used to describe the blast loads obtained in this study.…”

Experimental and Numerical Research on Cylindrical Tubes under Outer Cylindrical Explosive Waves

“…Numerical Model. Numerical simulations were conducted to investigate the detailed response of the tube subjected to a cylindrical explosive wave [22,23]. The commercial software AUTODYN was used to carry out the numerical simulation.…”

Inelastic dynamic response of square membranes subjected to localised blast loading

“…In fact, an extensive program of experimental and numerical studies has examined large deformation, damage evolution and failure of plates subject to uniform or localised impulsive loads. An extensive series of these studies are conducted by Nurick and co-authors [2]- [7] and by Børvik et al [8]- [11], while the main thrust of theoretical work commenced after the seminal work of Hopkinson and Prager [12]. Following their research, the dynamic plastic collapse of the rigid, perfectly plastic plates of various characteristic dimensions have been investigated [13]- [22].…”

“…It is further assumed that 0 > / . With reference to the velocity profile in Eq.s'(14) and(11) andFig. 6, the total external energy rate is compiled as:…”