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Numerical Prediction of Statistical Masonry Wall Fragment Distribution Induced by Blast Loading

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Transactions of Tianjin University 2008年第6期14卷 409-413页

作者：汪明郝洪丁阳李忠献 School of Civil Engineering Tianjin University School of Civil and Resource Engineering the University of Western Australia

The hazard caused by the fragments of damaged structures is usually significant in acci-dental explosions or hostile blast events.A reliable and efficient method to estimate probable fragment size,velocity and launch distance will be useful to assess and design countermeasures to mitigate the possible fragment *** paper presents a numerical method for predicting the size and launch distance of the fragments caused by explosive damage of masonry *** simulations with different scaled distances are carried out,and the statistical distribution functions of the fragment size and launch distance in terms of the scaled distance are derived.

关键词：碎片大小发射距离砌筑墙统计分布

Evaluation of Blast-Resistant Performance Predicted by Damaged Plasticity Model for Concrete

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Transactions of Tianjin University 2008年第6期14卷 414-421页

作者：还毅方秦陈力张亚栋 Engineering Institute of Corps of Engineers PLA University of Science and Technology

In order to evaluate the capacity of reinforced concrete (RC) structures subjected to blast loadings,the damaged plasticity model for concrete was used in the analysis of the dynamic responses of blast-loaded RC structures,and all three failure modes were numerically simulated by the finite element software *** results agree with the experimental *** is demonstrated that the damaged plasticity model for concrete in the finite element software ABAQUS can predict dynamic responses and typical flexure,flexure-shear and direct shear failure modes of the blast-loaded RC structures.

关键词： ABAQUS 混泥土破损度可塑性承重力修复方法

Numerical Simulation of Water Mitigation Effects on Shock Wave with SPH Method

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天津大学学报：英文版 2008年第5期14卷 387-390页

作者：毛益明方秦张亚栋高振儒 Engineering Institute of Corps of Engineers PLA University of Science and Technology

The water mitigation effect on the propagation of shock wave was investigated numerically. The traditional smoothed particle hydrodynamics (SPH) method was modified based on Riemann solution. The comparison of numerical results with the analytical solution indicated that the modified SPH method has more advantages than the traditional SPH method. Using the modified SPH algorithm, a series of one-dimensional planar wave propagation problems were investigated, focusing on the influence of the air-gap between the high-pressure air and water and the thickness of water. The numerical results showed that water mitigation effect is significant. Up to 60% shock wave pressure reduction could be achieved with the existence of water, and the shape of shock wave was also changed greatly. It is seemly that the small air-gap between the high-pressure air and water has more influence on water mitigation effect.

关键词：冲击波黎曼几何解 SPH 光滑颗粒

Simplified Analysis for Reflective Overpressure on Walls of Rectangle-Section Tunnel due to Its Inner-Explosion

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Transactions of Tianjin University 2008年第5期14卷 363-370页

作者：田力李忠献周清 School of Civil Engineering Tianjin University

Based on the constructing thought of the displacement model of isoparametric finite element, an extended interpolating algorithm is deduced for calculating the overpressure history of an optional point on the walls of the rectangle-section tunnel under an optional point-explosion in its internal space. According to the working principle, the overpressure histories of all nodes on the walls of a tunnel with the equal width and height of 2 m, induced by a reference-charge explosion at each node in this tunnel's cross section, are computed using the LS-DYNA software, and then are gathered to establish a reference database, which makes it possible to set optionally the positions of the explosive and the overpressure-observed point. In addition, some variation factors of peak values and durations of overpressure on the walls, reflecting some changes on the charge weight and the sizes of width and height of the section, are included in this algorithm in order to simulate approximately the overpressure responses on the walls under the optional charge weight and cross-section size. Some example analyses indicate the rapidity and validity of this method, and therefore this will bring it a good prospect in engineering application.

关键词：矩形面隧道参考数据爆破力装药量

Methods for Progressive Collapse Analysis of Building Structures Under Blast and Impact Loads

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天津大学学报：英文版 2008年第5期14卷 329-339页

作者：李忠献师燕超 School of Civil Engineering Tianjin University

Progressive collapse of building structures under blast and impact loads has attracted great attention all over the world. Progressive collapse analysis is essential for an economic and safe design of building structures against progressive collapse to blast and impact loads. Because of the catastrophic nature of progressive collapse and the potentially high cost of constructing or retrofitting buildings to resist it, it is imperative that the progressive collapse analysis methods be reliable. For engineers, their methodology to carry out progressive collapse evaluation need not only be accurate and concise, but also be easily used and works fast. Thus, many researchers have been spending lots of effort in developing reliable, efficient and straightforward progressive collapse analysis methods recently. In the present paper, current progressive collapse analysis methods available in the literature are reviewed. Their suitability, applicability and reliability are discussed. Our recent proposed new method for progressive collapse analysis of reinforced concrete frames under blast loads is also introduced.

关键词：进展性滑坡建筑结构冲击负载分析方法

Numerical Analysis of Dynamic Behavior of RC Slabs Under Blast Loading

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Transactions of Tianjin University 2009年第1期15卷 61-64页

作者：都浩李忠献 School of Civil Engineering Tianjin University

In order to reduce economic and life losses due to terrorism or accidental explosion threats, reinforced concrete (RC) slabs of buildings need to be designed or retrofitted to resist blast loading. In this paper the dynamic behavior of RC slabs under blast loading and its influencing factors are studied. The numerical model of an RC slab subjected to blast loading is established using the explicit dynamic analysis software. Both the strain rate effect and the damage accumulation are taken into account in the material model. The dynamic responses of the RC slab sub-jected to blast loading are analyzed, and the influence of concrete strength, thickness and reinforcement ratio on the behavior of the RC slab under blast loading is numerically investigated. Based on the numerical results, some prin-ciples for blast-resistant design and retrofitting are proposed to improve the behavior of the RC slab subjected to blast loading.

关键词：数值分析加动态特性源码钢筋混凝土柱动力响应

Mesh Size Effect in Numerical Simulation of Blast Wave Propagation and Interaction with Structures

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Transactions of Tianjin University 2008年第6期14卷 396-402页

作者：师燕超李忠献郝洪 School of Civil Engineering Tianjin University School of Civil and Resource Engineering The University of Western Australia

Numerical method is popular in analysing the blast wave propagation and interaction with ***,because of the extremely short duration of blast wave and energy trans-mission between different grids,the numerical results are sensitive to the finite element mesh *** numerical simulations show that a mesh size acceptable to one blast scenario might not be proper for another case,even though the difference between the two scenarios is very small,indicating a simple numerical mesh size convergence test might not be enough to guarantee accu-rate numerical ***,both coarse mesh and fine mesh were used in different blast scenarios to investigate the mesh size effect on numerical results of blast wave propagation and interaction with *** on the numerical results and their comparison with field test re-sults and the design charts in TM5-1300,a numerical modification method was proposed to correct the influence of the mesh size on the simulated *** can be easily used to improve the accu-racy of the numerical results of blast wave propagation and blast loads on structures.

关键词：网格尺寸效应数字模拟灵敏度冲击波传播荷载能力

门上设置弹簧与阻尼器的防护门抗爆性能的理论与数值分析

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振动与冲击 2010年第7期29卷 83-87页

作者：方秦杜茂林陈力解放军理工大学工程兵工程学院南京210007

采用理论与数值分析方法研究在门上设置弹簧和阻尼器提高防护门抗力的可行性及有效性。首先,利用第二类Lagrange方程,建立了门体上设置弹簧和阻尼器结构的三自由度等效体系简化分析模型,系统研究了刚度系数、阻尼系数和质量比对防护门... 详细信息

采用理论与数值分析方法研究在门上设置弹簧和阻尼器提高防护门抗力的可行性及有效性。首先,利用第二类Lagrange方程,建立了门体上设置弹簧和阻尼器结构的三自由度等效体系简化分析模型,系统研究了刚度系数、阻尼系数和质量比对防护门动力响应的影响特点与规律,结果表明:仅在刚度系数和阻尼系数较小的情况下,上述措施可以有效降低防护门的跨中位移,但此时门上辅助结构的位移太大;在刚度系数较大而阻尼系数较小的情况下,防护门与门上辅助结构之间存在共振现象;在刚度系数和阻尼系数都足够大的情况下,上述措施作用仍然十分有限。其次,对典型的防护门结构进一步进行了精细化非线性有限元分析,计算结果再一次表明门上设置弹簧和阻尼器难以有效提高防护门抵抗核爆和化爆荷载的能力。

关键词：防护门爆炸荷载弹簧阻尼器抗力

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爆炸荷载作用下钢框架结构连续倒塌分析

北京工业大学学报 2013年第7期39卷 986-993页

作者：杜修力石磊北京工业大学建筑工程学院北京100124

结合美国GSA规范,采用显式有限元软件LS-DYNA,建议了一套完整的爆炸激励下结构倒塌数值计算分析方法,并对一栋4层钢框架结构在爆炸荷载作用下的连续倒塌过程进行了仿真分析,研究了钢框架结构的连续倒塌机制、各结构构件的破坏形式和受... 详细信息

结合美国GSA规范,采用显式有限元软件LS-DYNA,建议了一套完整的爆炸激励下结构倒塌数值计算分析方法,并对一栋4层钢框架结构在爆炸荷载作用下的连续倒塌过程进行了仿真分析,研究了钢框架结构的连续倒塌机制、各结构构件的破坏形式和受力状态.本文建议的方法可以较为真实、准确地模拟结构在爆炸激励下的倒塌全过程.进一步的研究还发现:当部分结构构件被炸坏后,结构倒塌过程中,悬链线机制对结构的倒塌形式和构件的渐进破坏形式产生很大影响;悬链线拉力直接或间接导致了结构构件的局部翘曲和整体塑性失稳.

关键词：爆炸钢框架连续倒塌数值模拟