| 窦铁生,董晓农,牛文龙,李炎隆,宁靖华,黎康平.PCCP断丝破坏规律Ⅱ：数值模拟研究[J].水利学报,2024,55(1):48-59,70 |
| PCCP断丝破坏规律Ⅱ：数值模拟研究 |
| Failure law of PCCP caused by broken wires Ⅱ：Numerical simulation study |
| 投稿时间：2023-07-08 |
| DOI：10.13243/j.cnki.slxb.20230413 |
| 中文关键词: PCCP 集中断丝 离散断丝 数值模拟方法 预应力损失 破坏 |
| 英文关键词: PCCP clustered wire breakage scattered wire breakage numerical simulation method prestress loss failure |
| 基金项目:水利部重大科技项目(SKS-2022111);陕西省自然科学基础研究计划——引汉济渭联合基金项目(2019JLZ-14) |
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| 中文摘要: |
| 目前预应力钢筒混凝土管(Prestressed Concrete Cylinder Pipe，PCCP)断丝的数值模拟要么整圈删除断丝，要么将断丝的预应力损失范围假设为固定值，无法依据砂浆损伤程度来判断断丝预应力损失范围是否扩展。本文通过抽象分析砂浆、预应力钢丝和管芯混凝土之间的两两相互作用机制，引入弹簧单元、内聚力模型和塑性损伤模型，提出了管芯混凝土预压应力施加、任意位置钢丝割断和断丝预应力损失范围扩展的全过程模拟方法，明确了调控断丝预应力损失范围的初始大小、扩展时机和扩展幅度的关键参数。基于原型试验建立了恒定内压下集中和离散断丝的数值模型，从内压加载到断丝破坏的全过程角度验证了新模拟方法的合理性，揭示了管芯的预应力损失和破坏规律，使实际工程中各种三维断点分布的模拟成为可能，可为更精准地预测和评估断丝PCCP结构性能提供新手段。 |
| 英文摘要: |
| Numerical simulation of wire breakage in prestressed concrete cylinder pipes (PCCP) currently either removes the entire circle containing the broken wire or assumes a fixed range in each broken wire regaining its full tension，without considering whether this range due to mortar damage can be extended.This paper abstractly analyzes the interaction mechanisms between the mortar，steel wires，and core concrete of PCCP，introduces the spring element，cohesive contact model，and concrete plastic damage model，proposes a full-process simulation method for prestressing the core concrete，cutting steel wires at arbitrary position，and forming an extendable range in each broken wire regaining its full tension，and clarifies the key parameters for regulating the initial size，extension timing，and extension amplitude of this range.Based on prototype tests，numerical models were established for clustered and scattered wire breakage under constant internal pressure，and the rationality of the new simulation method was verified from the perspective of the entire process from internal pressure loading to wire breakage failure.And these reveal the laws of the prestress loss and failure of the core，make it possible to simulate various three-dimensional breakpoint distributions in practical engineering，and provide a new means for more accurate prediction and evaluation of the structural performance of the wire-broken PCCP. |
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