关于市政给排水工程几个关键问题的研究

首先讨论了给排水系统,接着分析了铝塑复合管(PAP)﹑HDPE管的接口方式﹑管材管件的有见证送检及检验依据﹑夹砂玻璃钢管(RPMP)的施工,最后研究了施工安全管理和施工质量管理。因此本文具有深刻的理论意义和现实的应用指导价值。     

高密度聚乙烯新管材在港口工程中的应用

介绍高密度聚乙烯(HDPE)排水管道的特点、设计、安装等问题。并论述这种新型管材在港口工程中的应用意义。     

浅析高密度聚乙烯（HDPE）管道的施工工艺及造价分析

高密度聚乙烯（HDPE）管道刚开始从国外引进，在我国工程领域中使用时间不长。文章在分析HDPE管道特性的基础上，介绍了HDPE管道的施工工艺及安装控制要点，指出管道施工中应注意的问题，以保证HDPE管道的施工质量；同时分析了HDPE管道的施工造价。对此类工程有借鉴意义。     

基于中美欧标准的HDPE消防管道压力试验对比

坦桑尼亚某水工项目堆场采用HDPE作为消防管道。HDPE为低模量黏弹性材料管道,加压时HDPE材料会发生自限性蠕变膨胀。由于聚乙烯分子链在高应力下伸展,管内填充水的压力会在试验测试时间内略微下降,这并不意味着管道泄漏,而是蠕变塑性管道的正常行为。与刚性管道相比,HDPE压力试验的测试方法会有不同。以中国规范GB 50268—2008、欧洲规范BS EN 805:2000和美国规范ASTM F2164-18为基础,对比分析HDPE管道的消防压力试验,为后续相关项目提供经验参考。     

PCCP管材在长春市一、四热电厂联合备用水源供水工程中的应用

PCCP管材在一、四热备用水源供水工程的应用,提出PCCP管材应用分析、施工中注意事项及在工程中应用PCCP管材的效果。     

大型HDPE管在电厂取排水工程中的应用

大型HDPE管(High Density Polyethylene高密度聚乙烯)是海上取排水设计中的一种新型结构型式,目前尚无统一的设计施工标准规范。本文通过菲律宾某电厂取排水工程大型HDPE管道应用实例,分析介绍其设计和施工方法,以期为类似工程提供借鉴和参考,对优化海上取排水设计具有重要的工程意义。     

浅谈大型HDPE管道海上出运安装施工工艺

HDPE管具有耐腐蚀、内壁光滑、流动阻力小、强度高、韧性好、重量轻等特点,广泛应用于内河外海等排水工程。本文以卡塔尔Lusail北部排水口1,400mm HDPE管道海侧安装施工为依据,结合当地特定的气候及地理条件,通过理论结合实践经验,对大型HDPE管道在陆侧出运及海上安装工艺进行较为详细分析,亦为今后类似工程提供借鉴思路。     

村镇供水工程常用管材选择

各类输水管材在自重、施工安装、耐压性能、耐腐蚀性、使用寿命等各具特点,由于不同村镇供水工程在供水规模、供水水质、管线水文地质条件、工程造价方面都存在较大差异,因此选择适应于相应工程的供水管材,不仅对该供水工程的建设、造价可进行有效控制,而且可以降低工程的运行管护费用。     

浅谈城市给水PE管热熔连接法施工技术

PE管重量轻、韧性好、施工方便,是城镇供水较为理想的管材。文章就PE管采用热熔连接法施工要点及质量检查等进行了论述。     

船舶上建供排水系统管材的选用比较

文章根据船舶上建供排水系统介质的特点,描述了系统及其使用的各种管材的特性,同时对各种管材在质量、价格、设计、施工等各方面进行对比,得出结论 :不锈钢管和紫铜管仍将继续使用,但塑料管优势明显,其应用会越来越广泛。     

船舶机舱使用塑料管作为通风导管要求分析

通过现场检查发现部分船舶私自增设聚氯乙烯管作为通风导管,结合适用的技术规范分析船舶机舱使用塑料管作为通风导管需满足的要求,提出对使用塑料管作为通风导管的船舶进行检查时应注意的事项.     

Stress concentration factors at welds in pipelines and tanks subjected to internal pressure and axial force

In this paper, analytical expressions for stress concentration factors in pipes subjected to internal pressure and axial force are derived for a number of design cases based on classical shell theory. The effect of fabrication tolerances in simple butt welds is assessed. Analyses based on classical mechanics are compared with results from axisymmetric finite element analyses for verification of the presented methodology. Stress concentration factors are presented for circumferential butt welds in pipes welded together from pipes with different thicknesses, welds at buckling arrestors, welds at flanged connections in pipelines, and welds at ring stiffeners on the inside and the outside of the pipes. It also includes stress concentration factors at end closures in pipes for gas storage. Larger pipes are fabricated from plates with a longitudinal weld. This fabrication process introduces out-of-roundness in the pipes. The actual out-of-roundness is a function of internal pressure. An analytical expression for the bending stress in the pipe wall due to this out-of-roundness is presented. The derived stress concentration factors can be used together with a hot spot stress S–N curve for calculation of fatigue damage.     

船用复合材料管路振动特性试验研究

为研究船舶中复合材料充液管路的减振特性,首先采用几何尺寸相同的复合材料直管和钢直管进行振动响应对比分析。通过直管的四端阻抗测试,获得2种材料直管的传递矩阵,对比分析复合材料管路与钢管的振动传递损失。然后对2种材料直管进行自由边界下的模态测试,获取管路的阻尼系数。试验结果表明:在满足输水性能和结构强度的前提下,复合材料管路只是同几何尺寸钢管质量的一半,复合材料管的固有模态频率要低于钢管,模态阻尼系数却远大于钢管。在2500 Hz内复合材料管的横向振动传递损失优于钢管;而轴向传递损失在低频段要劣于钢管,高频段又优于钢管。因此在减振性能上,复合材料管更利于振动能量在传播过程中的衰减。研究成果可为复合材料在船舶充液管路减振降噪中的应用提供参考。     

三类边界条件下隔水套管涡激非线性振动的分析研究

考虑流及波流联合作用,研究了套管的涡激非线性振动.将套管简化为梁模型,考虑3类不同的边界条件,计及莫里森非线性流体动力和涡激荷载,建立套管的涡激振动方程.应用克雷洛夫函数求解套管的固有频率和模态,采用了计算涡激非线性动力响应的迦辽金方法.以东海勘探3号钻井隔水套管为例,研究了不同边界条件下流引起的主共振和波流联合引起的组合共振.计算结果表明:流对套管的动力响应占主导地位,而波的影响不大.分析了3类不同边界条件下隔水套管的涡激非线性动力响应,揭示了波流联合激励下套管复杂的动力响应特性.     

固定支架式双壁管的预制安装方法

为推广双壁管预制及安装技术,详细描述45 000m3 LNG运输船采用的一种固定支架式燃气双壁管的预制安装过程,主要包括双壁管的结构特点,几种基本型双壁管的成形方法与焊缝焊接顺序,双壁管在船上安装、试压及清洗的工序特点、难点和注意事项,可作为类似项目管理团队及相关人员的参考。     

深水管中管结构动态边界条件非线性时域分析

随着海洋油气开发工程作业水深的增加,管中管结构承受的波浪、海流深海环境载荷增大,可能会引发强度破坏以及疲劳损伤,造成重大损失,所以开展深水条件下管中管系统的力学行为分析研究是有必要的。本文考虑了顶部张紧力和动态边界,利用有限元模型来模拟管中管结构及其力学行为。并利用接触单元模拟内外管接触的约束条件。综合统计了管柱的接触碰撞位置和应力危险位置,提出了新型扶正器的布置方案,以达到减缓碰撞保护管柱的目的,并对比了等距离设置扶正器的方案。通过对比研究发现本文提出的扶正方案有效减缓了内外管的应力等级,对于实际工程和研究具有一定指导价值。     

On the effect of the ply stacking sequence on the failure of composite pipes under external pressure

The use of high performance structural composites has become very important over the last decades, especially where weight is an essential factor. Particularly in the oil and gas industry, several designs of composite pipes for deep water applications have been recently proposed as competitive solutions against traditional steel pipes. Thus, it is important to assess the performance of composite pipes under high external pressure in order to avoid pipe failure or overconservative designs. In this paper, experimental tests of different composite pipe configurations are performed and then compared to analytical and numerical predictions. Unlike the case of internal pressure loads, the collapse pressure of composite pipes depends on the initial ovality and on the ply stacking sequence. The collapse resistance of different composite pipes is firstly studied through simplified analytical equations combined with different failure criteria. Then, a finite element model is developed using a progressive failure criterion [1]. Both analytical and numerical failure predictions were compared to experimental tests carried out on four composite pipes produced with different ply stacking sequence by the filament winding method [2]. An experimental-numerical-analytical comparison shows that numerical and analytical models provide results in good agreement with those obtained experimentally. Finally, a parametric analysis is carried out to show the effect of ovality and ply stacking sequence on the failure pressure of composite pipes.     

挠性接管对管壁弯曲振动的隔离性能分析

采用分析软件ANSYS就理想情况下袖套式挠性接管在不同的边界条件和布置情况下，对管路中沿管壁传播的弯曲振动的隔离性能分析表明，挠性接管在大部分频段上能有效的隔离弯曲振动，但也有可能使振动放大，这与其边界条件和布置情况密切相关，由此对挠性接管的布置安装提出建议.     

考虑应变强化效应海底管道极限承载力研究

文章基于线性强化材料模型,推导了轴向拉力作用下海底管道极限弯矩承载力解析解,给出了海底管道在轴向拉力与弯矩载荷同时作用下的极限承载力的近似解,编制了海底管道极限承载力计算程序BCP。通过与实验结果的比对,验证了解析方法的正确性。结论表明考虑应变强化效应的海底管道极限承载力结算结果更为合理,该文可为海底管道的结构强度设计和安全性评价提供一定的参考依据。     

Effects of longitudinal fins on dynamic stability of pipes conveying fluid made of functionally graded material

Dynamic behavior and instability of clamped-clamped pipes conveying fluid with longitudinal fins are studied in this paper. The analysis is done for pipes made of both homogeneous and functionally graded materials (FGM). In the FGM case, the materials of pipe and fins are assumed to be graded through the radial direction based on a power-law distribution. The Hamiltonian principle and Euler-Bernoulli beam assumptions are employed to derive the governing differential equations of the pipe system. Different fin configurations are investigated and the effects of several parameters including power‐law index, fluid velocity, number of fins, thickness and height of the fins are analyzed. Natural frequencies of the pipe and critical flow velocities are determined for various values of parameters. Numerical results show that the stability of the system is significantly affected by the power‐law index and fin dimensions. Among different fin configurations studied in this paper, the addition of non-horizontal fins provides significant improvement in the stability of both homogeneous and FGM pipes conveying fluid and consequently, can be considered as an effective “dynamic stabilizer” for the pipe system. In contrast to non-horizontal fins, the horizontal fins improve the stability of pipes conveying fluid, slightly.