Pressure-Impulse Diagrams for Blast Loaded Continuous Beams Based on Dimensional Analysis

Abstract

This paper studies pulse loading shape effects on the dynamic response of continuous beams. The beam is modeled as a single span with symmetrical semirigid support conditions. The rotational spring can assume different stiffness values ranging from 0 (simply supported) to oo (fully clamped). An analytical solution for evaluating displacement time histories of the semirigidly supported (continuous) beam subjected to pulse loads, which can be extendable to very high frequency pulses, is presented in this paper. With the maximum structural deflection, being generally the controlling criterion for damage, pressure-impulse diagrams for the continuous system are developed. This work presents a straightforward preliminary assessment tool for structures such as blast walls utilized on offshore platforms. Eor this type of structures with semirigid supports, simplifying the whole system as a single-87-92) to eliminate pulse loading shape effects on pressureimpulse diagrams would be very conservative and cumbersome considering the support conditions. It is well known that an SDOF model is a very conservative simpliflcation of a continuous system. Dimensionless parameters are introduced to develop a unique pulse-shape-independent pressure-impulse diagram for elastic and elastic-plastic responses of continuous beams.

Pressure−impulse diagram method – a fundamental review

“…M. Li and Meng, 2002b;Nystrom, 2006;Campidelli and Viola, 2007;Fallah and Louca, 2007;W. Wang et al, 2012a;Fallah et al, 2013;Parlin et al, 2014;Chernin et al, 2016). This sensitivity can partially be considered by building additional curves reflecting the variation in a certain parameter, e.g.…”

“…W. Ma et al, 2007;H. J. Shi et al, 2012;Fallah et al, 2013;Yu et al, 2018). The latter method is discussed in Sections 3.3 and 4.1.…”

“…M. Li and Meng, 2002b;Rhijnsburger et al, 2002;Ng and Krauthammer, 2004;Soh and Krauthammer, 2004;Blasko et al, 2007;G. W. Ma et al, 2007;Fallah et al, 2013)…”

“…W. Ma et al, 2007;Krauthammer et al, 2008;PDC, 2008;Yanchao Shi et al, 2008;USACE, 2008;Cormie et al, 2009;El-Dakhakhni et al, 2009;Razaqpur et al, 2009;CCPS, 2010;Dusenberry, 2010;Yanchao Shi et al, 2010;Mutalib and Hao, 2011; H. J. Shi et al, 2012;Astarlioglu et al, 2013;Ding et al, 2013;Fallah et al, 2013;Nassr et al, 2013;Thiagarajan et al, 2013;Xihong Zhang et al, 2013), as well as for evaluation of the safe stand-off distance using additional 'range-charge weight' overlays (Abrahamson and Lindberg, 1976;Mays and Smith, 1995;Cormie et al, 2009). This method relates the structural response of beams, plates, shells and other structural elements to an applied load with a specific peak pressure and impulse (Westine and Baker, 1975;Westine and Cox, 1975;BRL, 1976) and is recommended by various design codes (Command, 1986; Departments of the Army, 1990;TNO, 1992;USDE, 1992;CCPS, 1996;ASCE, 1997;PDC, 2008;USACE, 2008;Dusenberry, 2010).…”

A Predictive Model for Damage Assessment and Deformation in Blast Walls Resulted by Hydrocarbon Explosions

“…ese P-I diagrams strongly depend on pressure versus time expression (pulse shape) of the explosion [10], and together with SDOF modelling, they are used to find the blast response of complex of structures, such as cablesupported facades [11]. Both SDOF-type model [12] and continuous beam model [13] are used for developing P-I diagrams. Recently, it is shown that batch finite element simulations [14] cannot lead to P-I diagram unless preliminary information regarding SDOF parameters is available.…”