黑镜 百度云美甲学习班Tran s.Tian jin Univ.2010,16:395-404DOI 10.1007/s 12209-010-1410-6
Accept ed d at e:2010-06-09.
pengliSupported by Nati onal Natural Science Foundation of China (No.50678116),Nati onal Key Technology R&D Program of China (No.2006BAJ13B02),T j M M j j f F F T y R (N ZD 5)TI N L ,,,D ,f TI N L ,@j Simplified Computation of Reflective Overpressure in Clodspark
Cuboid Space D ue to Interna l Explosion *pollution作文>i promi
TI AN Li(田
加油用英语怎么说
力)1，LI Zhong xia n(李忠献)1，ZHOU Qing(周
清)2
(1.School of Civil Engineering,Tianjin University,Tianjin 300072,China ；2.Binzhou Urban Planning and Design Institute,Binzhou 256600,China)
Tianjin University and Springer-Verlag Berlin Heidelberg 2010
Ab stract ：A simplified method is propod for analyzing the overpressure history of an optional point on the walls of a clod cuboid due to its internal optional point-explosion.Firstly,the overpressure histories of all nodes on the walls of a cube with a side-length of 2m are computed under a reference-charge explosion at each node of its inner space using the LS-DYNA software,and then are collected to form a reference databa.Next,with the thought of the isoparametric finite element,an interpolating algorithm is established to calculate the overpressure history of an op-tional point on the walls induced by an explosion at any position inside this cubic space.Then,some ratio factors of peak values and durations of overpressure on the walls,reflecting changes in the charge weight and side-length of a cuboid,are derived and applied subquently,together with their contributing coefficients,to make some modifica-tions to the above algorithm,which achieves an approximate simulation to the overpressure histories on the walls un-der the optional charge weight and cuboid size.Finally,example results verify the rapidity and validity of this method,and provide feasible ranges of the charge weight and cuboid size according to the current computing condition.Keyword s ：clod cuboid space;reference databa;reflective overpressure;charge weight
With the speedup of urbanization and expansion of population in cities,there are increasing undergro
und structures having been or being constructed in cities to relea tension from the under -supply of land for build-ings.It is predictable that in such confined structure spaces a bomb attack by terrorists probably results in more life loss and structure damage than in the above-ground ones.Hence,to study the respons and damage mechanism of underground confined structures subjected to inner explosion,an appropriate simulation of the over-pressure histories on walls of tho structures has to be carried out in advance.Although some achievements in this field have been obtained numerically and experimen-tally by some scholars,such as Baker et al [1],Smith et al [2],Pritchard et a l [3],Lee [4],Louca et al [5],Feldgun et a [6]
,Yang et al [7],Rao et al [8],Liu et al [9],Wang et al [10],and Li et a l [11],there still exist some limitations in tting the sizes of confined spaces,the positions of the explo-sion source and the overpressure -obrved points,and the TNT charge weight.Thus,a simplified analysis is pro-pod for the overpressure history on the walls of a clod cuboid space with optional length of side s ,caud by a blast load of an optional charge weight at an op-tional position in this space.A ries of algorithms with high accuracy are derived,remarkably reducing the com-puting time of overpressure histories.The analysis proc-ess includes four steps as follows.First,two discretiza-tion models about a cubic space with a side -length of 2m and one of its walls are established with the 8-node cubic an
英语免费学习网站d 4-node square finite element techniques respectively,and then overpressure histories of element nodes of this wall,induced by an explosion of 0.205kg TNT at each node of this space,are computed using the LS -DYNA software [12]and subquently collected to form a refer-ence databa.Second,an interpolating algorithm of overpressure at an optional point of this wall under an explosion of 0.205kg TNT at an optional point inside this space is put forward according to the constructing idea of displacement function of the isoparametric ele-ment [13,14].Third,some ratio factors of peak values and durations of overpressure on the wall corresponding to the changes of the charge weight and the cuboid size,along with their contributing coefficients,are propod to make some modifications to the above algorithm so that
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Correspondence to A i E-mail:ltian t u.edu.
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