气云爆炸下混凝土结构的动力响应和损伤评估

发布时间：2018-01-19 03:07

本文关键词： 气云爆炸动力响应损伤评估超压冲量曲线　出处：《南京理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着石油化工业的发展,生产规模的扩大,气云爆炸事故多发,不仅威胁人们的生命财产安全,也会祸及周围建筑结构,造成结构破坏甚至整体倒塌。目前关于气云爆炸的研究进展较慢,急需展开关于气云爆炸下结构破坏效应的深入研究。本文在气云爆炸下理想弹性体动力响应的理论分析的基础上,采用数值模拟方法,研究分析了钢筋屈服强度、钢筋间距、气云半径因素对气云爆炸下抗爆墙的动力响应的影响规律；选用超压冲量破坏准则,以支座转角作为损伤评估指标,计算出气云爆炸下抗爆墙的损伤等级评估超压冲量P-I曲线,并分析了钢筋屈服强度、钢筋间距和抗爆墙的墙厚因素对损伤等级评估超压冲量P-I曲线的影响；根据超压冲量P-I曲线拟合出损伤等级评估公式。研究的主要结论：(1)抗爆墙裂缝主要集中在迎爆面四周和背爆面中部这些受拉部位,在裂缝周围的混凝土和钢筋出现应力重分布现象。气云爆炸冲击波作用结束前,在迎爆面中部和背爆面四周的受压区域显现少量裂缝。(2)钢筋屈服强度对抗爆性能的提高微乎其微,提高幅度最大的为0.89%。相较之下减小钢筋间距可适当减弱抗爆墙的动力响应,减弱幅度为2.80%-10.54%不等,而气云半径对钢筋混凝土抗爆墙的动力响应影响最为显著,影响幅度最小可达到51.19%。(3)增加墙厚使P-I曲线向右上方移动,墙厚对损伤程度的影响最为显著,同等超压值下冲量增幅最小为31.728%,最大的增幅为225.104%。钢筋间距对损伤程度的影响较大,同等超压值下冲量增幅在4.5%-9.5%左右,钢筋屈服强度对对损伤程度的影响最弱,同等超压值下冲量增幅在2%左右,最小增幅为0.45%,接近于O。
[Abstract]:With the development of petrochemical industry, the expansion of production scale, gas cloud explosion accidents, not only threaten the safety of people's lives and property, but also damage the surrounding building structure. At present, the research progress of gas cloud explosion is slow. In this paper, based on the theoretical analysis of the dynamic response of the ideal elastic body under the gas cloud explosion, the numerical simulation method is adopted. The influence of the yield strength of steel bar, steel bar spacing and the radius of gas cloud on the dynamic response of anti-explosion wall under gas cloud explosion is studied and analyzed. According to the criterion of overpressure impulse failure and the angle of bearing as the damage evaluation index, the P-I curve of damage grade evaluation of anti-explosion wall under the explosion of gas cloud is calculated, and the yield strength of steel bar is analyzed. The influence of the steel bar spacing and the wall thickness of the anti-explosion wall on the P-I curve of the damage grade evaluation of the overpressure impulse; According to the P-I curve of overpressure impulse, the damage grade evaluation formula is fitted. The main conclusion of the study is that the crack of anti-explosion wall is mainly concentrated around the face of the explosion and the middle of the back surface. Stress redistribution occurs in the concrete and steel bar around the crack. In the middle of the face and around the back blasting surface, a small amount of cracks. 2) the yield strength of steel bar is improved very little. The maximum increase range is 0.89.The dynamic response of the anti-explosion wall can be weakened by decreasing the steel bar spacing, which ranges from 2.80% to 10.54%. The influence of the radius of gas cloud on the dynamic response of reinforced concrete anti-explosion wall is the most significant, and the minimum influence range can reach 51.19 and increase the thickness of the wall to make the P-I curve move to the upper right. The effect of wall thickness on damage degree is the most significant, the minimum increase of impulse is 31.728 under the same overpressure, and the biggest increase is 225.104. The distance between steel bars has a great influence on the damage degree. The increase of impulse is about 4.5% -9.5% under the same overpressure value. The yield strength of steel bar has the weakest effect on the damage degree. The impulse increase is about 2% under the same overpressure value and the minimum increase is 0.45%. Close to O.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU311.3

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