﻿ 聚乳酸/碳纤维复合梯度材料在FPSO碰撞中力学性能研究
 舰船科学技术  2023, Vol. 45 Issue (20): 116-120    DOI: 10.3404/j.issn.1672-7649.2023.20.022 PDF

1. 江苏科技大学 船舶与海洋工程学院，江苏 镇江212100;
2. 江苏科技大学土木工程与建筑学院，江苏 镇江 212100

Polylactic acid/carbon fiber composite gradient material in FPSO collision mechanical performance research
YIN Qun1, LI Feng1, WANG ke1, SHEN Zhong-xiang2, DONG Guo-zhong1
1. School of Naval Architecture and Ocean Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China;
2. School of Civil Engineering and Architecture, Jiangsu University of Science and Technology, Zhenjiang 212100, China
Abstract: In this paper, polylactic acid (PLA)/carbon fiber composite gradient material is used to optimize the design of the protection structure of the FPSO outboard riser, and its protection effect is verified in terms of damage deformation, collision force and energy absorption characteristics of the protection structure, riser structure and outboard structure. The study shows that: four different PLA/carbon fiber distribution methods have improved the collision protection capability compared with mild steel protection structure; the structural strength, stress propagation and energy absorption characteristics are different with different PLA/carbon fiber mass fraction distribution methods, among which the X-type PLA/carbon fiber protection structure has the best collision protection performance and has certain engineering application value.
Key words: FPSO     PLA/carbon fiber composites     riser structure     anti-crash     mechanical properties
0 引　言

1 碰撞理论

 $M a+C v+K u=F(t)。$ (1)

 $M a_{n}+C v_{n}+K d_{n}=F_{n}^{u x t} 。$ (2)

 $M{a_n} = F_n^{{\rm{ext}}} - F_n^{{{\rm{int}}} } ，$ (3)
 $a_{n}=M^{-1} F_{n}^{\text {nemethat }}。$ (4)

 $a_{m t}=F^{\text {nendual }} / M_{\Delta}。$ (5)

 $v_{n+1 / 2}=v_{n-1 / 2}+a_{n}\left(\Delta t_{n+1 / 2}+\Delta t_{n-1 / 2}\right) / 2，$ (6)
 $d_{n+1}=d_{n}+v_{n+1 / 2} \Delta t_{n+1 / 2} 。$ (7)
2 复合梯度材料在FPSO碰撞中数值模拟 2.1 有限元模型

 图 1 FPSO与补给船有限元模型图 Fig. 1 Finite element model of FPSO and supply ship

 图 2 立管平台及防护结构有限元模型图 Fig. 2 Finite element model diagram of riser platform and protection structure
2.2 PLA/碳纤维复合梯度材料参数

2.3 新型PLA/碳纤维在防护结构中设计方案

2.4 计算工况

3 复合梯度材料在FPSO碰撞中力学性能计算结果与分析 3.1 立管应力特性计算结果与分析

 图 3 不同工况下被撞FPSO应力分布云图 Fig. 3 Stress distribution clouds of the struck FPSO under different operating conditions
3.2 复合梯度材料FPSO碰撞力结果与分析

 图 4 不同工况下被撞FPSO的碰撞力-时间曲线 Fig. 4 Collision force-time curves of FPSO under different working conditions
3.3 复合材料FPSO吸能结果与分析

 图 5 不同工况下被撞FPSO的结构吸能曲线 Fig. 5 Structural energy absorption curves of the struck FPSO under different operating conditions

4 结　语

1）碰撞载荷作用下，FPSO舷侧结构损伤具有很强的局部性，其损伤主要都集中在FPSO与补给船碰撞区域。在碰撞载荷作用下，无防护结构的FPSO损伤主要集中在立管结构，有防护结构的FPSO损伤主要集中在防护结构，立管结构变形损伤大幅降低。

2）典型补给船重量为1500t速度由3 m/s到5 m/s时，FPSO立管结构吸能量增加2.7倍，立管结构吸能占比由96%降到87%。随着补给船速度为5 m/s重量由1 500 t到3 000 t时，FPSO立管结构吸能量增加1.9倍，立管结构吸能占比由87%降到85%。这是由于随着补给船重量及速度的增加，FPSO舷侧结构的碰撞损伤范围增加，同时立管结构的吸能也大幅增大。

3）无防护结构下，立管为主要吸能构件，有防护结构下防护结构为主要吸能构件，典型工况下立管总体吸能降低31.4%，FPSO舷侧结构吸能变化不大。表明碰撞载荷作用下防护结构对立管结构具有较好的防护作用。

4）在相同重量及速度补给船的碰撞作用下，I，X，O，A四种PLA/碳纤维梯度材料的防护结构具有较好防护能力。其中X型梯度材料的防护结构较低碳钢材料的防护结构的碰撞力峰值提高62.5%；I，X，O，A四种PLA/碳纤维梯度材料的防护结构较低碳钢材料的防护结构吸能分别提高64.2%、74.1%、71.1%、59.2%。研究表明，4种设计方案中X型PLA/碳纤维梯度材料的防护结构下立管吸能少且防护结构防撞性能相对最好，其防护结构设计方案具有一定的工程应用价值。

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