An analysis method for the buckling process of a pipe section with a random pipelay imperfection is proposed. Four basic lateral modes, acquired by finite-element （FE） eigenvalue buckling analysis, are combined to p...An analysis method for the buckling process of a pipe section with a random pipelay imperfection is proposed. Four basic lateral modes, acquired by finite-element （FE） eigenvalue buckling analysis, are combined to provide the needed grid configurations for describing a real pipelay imperfection and an arc-length algorithm is used to analyze the snap-through process of the shell-element-grid model under nonlinear frictional boundary conditions. This paper also presents evaluation methods for the lateral buckling of two types of pipe-in-pipe systems that are used in the offshore oil and gas industry. For evaluating the buckling and postbuckling of compliant pipe-in-pipe systems FE analyses were carried out to judge the occurrence of the system buckling and furthermore to check postbuckling stresses induced in the buckles. The calculated results of the modified Riks algorithm indicate that only when high temperature would not trigger an abrupt short-wavelength buckle and when no yielding has been induced in the unavoidable long-wavelength buckles, the thermal stability and safety of compliant pipe-in-pipe systems can be proved. In the non-compliant pipe-in-pipe systems, firstly small-amplitude buckles of the carrier pipe may occur in the annulus between carrier pipe and casing pipe and the contact forces between the spacers and the casing pipe may drive the buckle of the pipe-in-pipe systems on the seabed. Based on the classical analytical solution of pipe buckling, four potential buckling modes corresponding to finite- element models are developed to evaluate the stability and the postbuckling strength of such pipe-in-pipe systems.展开更多
目的探讨复杂内耳畸形患儿人工耳蜗植入术后的听觉言语发育效果。方法回顾性分析2018年1月至2019年6月于西京医院行人工耳蜗植入术的17例复杂内耳畸形语前聋(内耳畸形组)患儿的临床资料,其中双侧植入1例,右侧植入8例,左侧植入8例,植入年...目的探讨复杂内耳畸形患儿人工耳蜗植入术后的听觉言语发育效果。方法回顾性分析2018年1月至2019年6月于西京医院行人工耳蜗植入术的17例复杂内耳畸形语前聋(内耳畸形组)患儿的临床资料,其中双侧植入1例,右侧植入8例,左侧植入8例,植入年龄1~10岁(平均3.49岁),男6例,女11例;IP-1畸形2例,IP-3畸形2例,共同腔2例,耳蜗发育不全11例(10例伴蜗神经发育不良)。随机选择同期性别、年龄、侧别相匹配的耳蜗结构正常的人工耳蜗植入患儿18例作为对照组。统计复杂内耳畸形围术期并发症,比较两组患儿术后1、3、6个月和1年的听觉行为分级标准(categories of auditory performance,CAP)、言语可懂度分级标准(speech intelligibility rating,SIR)、婴幼儿有意义听觉整合量表(infant-toddler meaningful culditory integration scale,IT-MAIS)、有意义言语使用量表(meanngful use of speech scale,MUSS)评分。结果内耳畸形组与对照组之间CAP、SIR评分在开机后6个月、1年无统计学差异(P>0.05);IT-MAIS评分在开机后1个月、3个月、6个月内耳畸形组低于对照组(P<0.05);MUSS评分在开机后3个月、6个月内耳畸形组低于对照组(P<0.05);CAP评分在开机后6个月、1年蜗神经发育不良组(10例)低于对照组(P<0.05)。结论复杂内耳畸形患儿人工耳蜗植入术后的听觉言语发育效果与内耳结构正常患儿相似,但伴蜗神经发育不良的内耳畸形患儿开机后1年听觉发育水平低于内耳结构正常的患儿。展开更多
Starting friction would be induced and preserved somewhere along the seabed route of cased insulated flowlines（CIF） when the pipe carries service loads.The axial pipe-soil interaction can be divided into three pipe ...Starting friction would be induced and preserved somewhere along the seabed route of cased insulated flowlines（CIF） when the pipe carries service loads.The axial pipe-soil interaction can be divided into three pipe sections：the sliding section,the fixed section and the starting friction section.Although limited to a relatively small length of the pipe,the pipe coats of the starting friction section would suffer much higher shear force caused by thermal expansion than those of the sliding section or the fixed section.Based on the axial equilibrium equation of this kind of insulated pipeline,we developed a method for checking the shear force on CIF coats and their interfaces.The typical example shows that starting friction effect should be taken into account when checking the lap shear strength of heatshrinkable sleeves on CIF field joints.展开更多
基金supported by the National Natural Science Foundation of China (No .50979113)
文摘An analysis method for the buckling process of a pipe section with a random pipelay imperfection is proposed. Four basic lateral modes, acquired by finite-element （FE） eigenvalue buckling analysis, are combined to provide the needed grid configurations for describing a real pipelay imperfection and an arc-length algorithm is used to analyze the snap-through process of the shell-element-grid model under nonlinear frictional boundary conditions. This paper also presents evaluation methods for the lateral buckling of two types of pipe-in-pipe systems that are used in the offshore oil and gas industry. For evaluating the buckling and postbuckling of compliant pipe-in-pipe systems FE analyses were carried out to judge the occurrence of the system buckling and furthermore to check postbuckling stresses induced in the buckles. The calculated results of the modified Riks algorithm indicate that only when high temperature would not trigger an abrupt short-wavelength buckle and when no yielding has been induced in the unavoidable long-wavelength buckles, the thermal stability and safety of compliant pipe-in-pipe systems can be proved. In the non-compliant pipe-in-pipe systems, firstly small-amplitude buckles of the carrier pipe may occur in the annulus between carrier pipe and casing pipe and the contact forces between the spacers and the casing pipe may drive the buckle of the pipe-in-pipe systems on the seabed. Based on the classical analytical solution of pipe buckling, four potential buckling modes corresponding to finite- element models are developed to evaluate the stability and the postbuckling strength of such pipe-in-pipe systems.
文摘目的探讨复杂内耳畸形患儿人工耳蜗植入术后的听觉言语发育效果。方法回顾性分析2018年1月至2019年6月于西京医院行人工耳蜗植入术的17例复杂内耳畸形语前聋(内耳畸形组)患儿的临床资料,其中双侧植入1例,右侧植入8例,左侧植入8例,植入年龄1~10岁(平均3.49岁),男6例,女11例;IP-1畸形2例,IP-3畸形2例,共同腔2例,耳蜗发育不全11例(10例伴蜗神经发育不良)。随机选择同期性别、年龄、侧别相匹配的耳蜗结构正常的人工耳蜗植入患儿18例作为对照组。统计复杂内耳畸形围术期并发症,比较两组患儿术后1、3、6个月和1年的听觉行为分级标准(categories of auditory performance,CAP)、言语可懂度分级标准(speech intelligibility rating,SIR)、婴幼儿有意义听觉整合量表(infant-toddler meaningful culditory integration scale,IT-MAIS)、有意义言语使用量表(meanngful use of speech scale,MUSS)评分。结果内耳畸形组与对照组之间CAP、SIR评分在开机后6个月、1年无统计学差异(P>0.05);IT-MAIS评分在开机后1个月、3个月、6个月内耳畸形组低于对照组(P<0.05);MUSS评分在开机后3个月、6个月内耳畸形组低于对照组(P<0.05);CAP评分在开机后6个月、1年蜗神经发育不良组(10例)低于对照组(P<0.05)。结论复杂内耳畸形患儿人工耳蜗植入术后的听觉言语发育效果与内耳结构正常患儿相似,但伴蜗神经发育不良的内耳畸形患儿开机后1年听觉发育水平低于内耳结构正常的患儿。
文摘Starting friction would be induced and preserved somewhere along the seabed route of cased insulated flowlines（CIF） when the pipe carries service loads.The axial pipe-soil interaction can be divided into three pipe sections：the sliding section,the fixed section and the starting friction section.Although limited to a relatively small length of the pipe,the pipe coats of the starting friction section would suffer much higher shear force caused by thermal expansion than those of the sliding section or the fixed section.Based on the axial equilibrium equation of this kind of insulated pipeline,we developed a method for checking the shear force on CIF coats and their interfaces.The typical example shows that starting friction effect should be taken into account when checking the lap shear strength of heatshrinkable sleeves on CIF field joints.
