非典型约束形式下海洋平台波纹板舱室抗爆能力评估

Assessment on explosion resistance capability for corrugated wall of cabin with atypical constraints on offshore platform

针对非典型约束条件即底部端面梁固定约束、其他各端面梁连接约束的海洋平台关键舱室,其波纹板舱壁在油气爆炸载荷下抗爆能力研究不足,采用数值模拟方法,结合考虑材料应变率效应的实验验证,分析爆炸载荷下舱壁动力响应及破坏模式。由传统位移指标不能准确评估该模型的抗爆能力,提出基于应变的评价指标,以此建立P-I评估曲线。研究表明舱壁与底部端面梁连接部位首先达到最大破裂应变发生破裂,其为超压与冲量共同作用结果;舱室可抵抗超压40 k Pa、冲量230 k Pa·ms的载荷而不发生塑性变形;舱室可抵抗超压85 k Pa、冲量400 k Pa·ms的载荷而不发生破裂。提出的以应变为指标的P-I曲线可量化舱壁损伤评估区间,结合爆炸载荷值,准确评估舱壁抗爆能力及损伤大小,为工程人员优化舱壁抗爆能力、确定灾后控制措施提供指导。

Aiming at the key cabins on offshore platform with atypical constraints,namely fixed constraints of end beams at the bottom and link constraints of other end beams,the study on explosion resistance capability for corrugated wall of cabin under the load of oil and gas explosion was insufficient. The dynamic response and failure mode of cabin wall under explosion load were analyzed by using numerical simulation method combined with experimental verification on strain rate effect of material. Because the explosion resistance capability of this model could not be assessed accurately by traditional displacement indexes,an evaluation index based on strain was proposed,thus the P- I assessment curve was established. The results showed that the maximum rupture strain was reached at first in the connection parts between the cabin walls and the end beams at the bottom of cabin,then the rupture occurred,which was caused by the combined action of overpressure and impulse. The cabin could resist the explosion load of 40 k Pa overpressure or 230 k Pa·ms impulse without plastic deformation,and it could resist the explosion load of 85 k Pa overpressure or 400 k Pa·ms impulse without rupture. The proposed P- I curve with strain as index can quantify the assessment range of wall damage,and assess the explosion resistance capability and damage of cabin wall accurately combined with the value of explosion load. It provides the guidance for engineers to optimize the explosion resistance capability of cabin wall and determine the post- accident control countermeasures.