Experimental and Numerical Investigations of Pressure Field of Curved Shell Structure Subjected to Interior Blast

Jialu Ma,Xudong Zhi,Lingxin Zhang,Chengqing Wu,Feng Fan

doi:10.1155/2019/9674274

Abstract

A terrorist attack on a long-span spatial structure would cause horrible results. Therefore, it is important to determine the characteristics of blast pressure fields to protect such structures. In this study, fully confined blast loading tests were conducted using a rigid curved shell model, which had an inner space similar to that of a reticulated dome. Four different scenarios were carried out to record the blast loading on five typical positions. The blast pressure-time data were compared and analyzed. In addition, a suitable numerical simulation method was proposed for the issues involved in interior blast loading. This numerical model was verified by comparing with the test data. A parametrical analysis of the interior blast simulations was conducted based on this numerical method. The blast loading values at specific positions were obtained with the key parameters varied within a reasonable scope. The blast loading from blast tests and simulations were presented. On this basis, the interior blast loading could conveniently be predicted by using the method and data in this paper, which could be used in the protective design of other reticulated domes.

Highlights

Long-span spatial structures with graceful configurations are always considered to be city landmarks
TNT cubes were used in the blast tests, because these were much easier to cut. e effects of charge shapes are mainly reflected in the near field of blast. e study in this paper focused on the interior blast loading of large-span spatial structures, of which the cases in this study are relating to far-field issues
Four scenarios with different TNT equivalences were used, and the pressure fields in the curved shell model were compared. e overpressures and impulses of the first peak for each scenario were compared and studied. e results showed that the first peaks had obvious regularity when the TNT equivalence was changed, whereas the subsequent blast loading peaks did not, which was caused by the complicated evolution process for the shock wave fields in the confined blast

Summary

Introduction

Long-span spatial structures with graceful configurations are always considered to be city landmarks. E US army presented the most authoritative guideline (UFC 3-340-02) [1], which was improved based on TM5-1300 It includes many blast issues with multiple situations regarding different structural types and shapes. The UFC guideline lacks information about special cases, which should be studied with extra specialized research using blast tests and numerical simulations. The blast loading on a long-span spatial structure is not clear and verified in the existing references, which is important for the protective design of structures. Single-layer reticulated domes, which are the most common type of long-span spatial structures, were taken as examples to investigate the pressure field distributions when subjected to an interior blast. Based on the numerical models, a parameter analysis was conducted to calculate the blast loading values of some standard cases, which could conveniently be used to estimate the blast loading values at specific positions for similar domes subjected to an interior blast

Setup of Blast Tests

Blast Loading Data from Tests

Numerical Model and Verification

Conclusions