蠕变试验装置的微机巡检系统

研制了微机巡检系统，巡回监测蠕变试验的温度和形变信号，介绍系统组成及其软件功能     

Fracture and creep of an Al2O3-SiC (whisker)-TiC (particle) composite

High-temperature fracture strength and compressive creep of an electrodischarge-machinable composite, Al₂O₃-30.9 vol.% SiC whiskers-23 vol.% TiC particles have been studied to 1200 °C and 1450 °C, respectively, in inert atmosphere. Microstructures of fractured and deformed specimens were examined using scanning and transmission electron microscopy. Fast fracture occurred at T ≤ 1200 °C. Steady-state creep was achieved for T > 1350 °C at stresses < 80 MPa, with the rate-controlling mechanism being partially unaccommodated grain-boundary sliding, with a stress exponent of ≈ 1 and an activation energy of≈ 470 kJ/mol.     

管道蠕变测量中温度测定的重要性

根据电力行业标准ＤＬ４４１－９１《火力发电厂高温高压蒸汽管道蠕变监督导则》中关于蠕变标记测量方法的要求，通过推导得到了测量温度的差值与换算到０℃时周长差值的关系式，并列举了北仑电厂实测得到的一些数据来进一上说明温度测量的重要性。     

Time-dependent analysis of RC frame structures considering construction sequences

This paper deals with a time-dependent analysis of reinforced concrete (RC) frame structures considering the construction sequences. Because of the non-mechanical deformations induced by the time-dependent deformations of concrete, concrete structures usually present different behaviors when the construction sequences are changed, despite having the same structural configurations. Therefore, the time-dependent effects of concrete such as creep and shrinkage must be taken into consideration to simulate the actual behavior of RC frame structures. The material nonlinearity including the cracking of concrete is taken into consideration, and geometric nonlinearity due to the P-Δ$\mathrm{\Delta }$ effect is also taken into account by using the initial stress matrix. In addition, the creep deformation of concrete is described in accordance with a first-order algorithm based on the expansion of a degenerated kernel of the compliance function. Finally, correlation studies with previous numerical results and experimental data are conducted to verify the validity of the proposed model. An analysis of a 10-story RC frame structure is carried out to assess the differences in structural responses according to the construction sequences.     

基于ABAQUS用户子程序的岩体非线性蠕变模型

建立了岩体非线性蠕变损伤演化方程,通过自行编制ABAQUS蠕变子程序,对圆形隧洞的开挖和蠕变后的力学行为进行了数值分析,实现了非线性蠕变本构模型的二次程序开发。     

Creep assessment of Zry-4 cladded high burnup fuel under dry storage

Cladding creep rupture is thought to be the most likely and limiting failure mechanism of spent fuel in dry storage. In spite of being highly unlikely, the current trend towards high burnups is drawing further attention to the potential creep effect on cladding integrity of fuels burnt over 45 GWd/tU.This paper explores the burnup influence on cladding creep during dry storage by modelling two different high burnup scenarios (51 GWd/tU and 67 GWd/tU). In addition, sensitivity of the results to the in-reactor average power and power history has been conducted. The computation tool used in this study has been an extension of FRAPCON-3.4 capable of simulating dry storage scenarios. Burnup and average linear power have been shown to make creep grow quite substantially during the first two years in dry storage, adopting a quasi-asymptotic trend from then on. However, even though this profile seems to have a generic nature, the net creep value reached depends not just on integral and average variables, but also on magnitudes describing the entire irradiation history, like linear power history. In none of the cases explored creep approaches the 1% threshold. In-reactor FGR modelling has been highlighted as a key element to get accurate estimates of creep.     

远近围岩含水不同对套管岩压外载的影响

建立了围岩多层性受载模型，按粘弹对应原理，对均匀地应力场下及非均匀地应力场下蠕变引起的岩压外载及因远近含水量不同而引起的变化，从理论上进行了分析。     

基于孔洞长大理论的多轴蠕变设计模型及其工程应用

多轴蠕变是高温构件失效的重要原因,工程设计中必须予以考虑.本文介绍了以孔洞长大理论为基础的多轴蠕变设计方法;探讨了孔洞长大的基本原理;讨论了基于该理论的5个常用模型;分析了这些模型在R5、ASME III、RCC-MR 及VGB-R 509L 中的应用,指出了高温构件多轴蠕变设计的困难,并对进一步的工作提出了建议.     

小型压水堆严重事故下一回路承压管道蠕变预测分析模型开发

一回路承压管道蠕变是压水堆核电厂严重事故重要现象之一。针对小型压水堆,本文基于SCDAP/RELAP5程序开发了严重事故分析模型,利用实验拟合方法得到了一回路主管道(SA321)、自然循环式蒸汽发生器传热管(00Cr25Ni35Al Ti)两种材料蠕变预测分析模型,改进了SCDAP/RELAP5程序蠕变预测分析功能模块,并通过假想事故序列验证了SA321、00Cr25Ni35Al Ti蠕变预测分析模型的合理性。为后续开展小型压水堆严重事故下一回路承压管道蠕变规律研究提供基础参考。