钢包包衬侵蚀对内衬温度和钢水温降的影响

为了研究包衬侵蚀对钢水温降的影响规律,通过ANSYS有限元软件以及ParaMesh网格随移技术建立了考虑包衬侵蚀的钢包传热计算模型,研究并分析了包衬侵蚀对包衬及钢水温度的影响规律。结果表明,包衬侵蚀对包衬温度影响较大,在相邻两个修包周期内,包衬侵蚀造成渣线和包壁的包衬内部(工作层与永久层交界处)温差为14～114 K;包衬侵蚀导致包壳外表面温度升高,包壳向外散热增加,与此同时,包衬受侵蚀变薄,蓄热减少,两者同时作用导致包衬侵蚀对钢水温降影响不大,最高不超过1 K,在实际生产中可以适当地忽略钢包侵蚀对钢水温降的影响。     

BIM-to-IGA: A fully automatic design-through-analysis workflow for segmented tunnel linings

Both planning and design phase of large infrastructural project require analysis, modelling, visualization, and numerical analysis. To perform these tasks, different tools such as Building Information Modelling (BIM) and numerical analysis software are commonly employed. However, in current tunnel engineering practice, there are no systematic solutions for the exchange between design and analysis models, and these tasks usually involve manual and error-prone model generation, setup and update. In this paper, focussing on tunnelling engineering, we demonstrate a systematic and versatile approach to efficiently generate a tunnel design and analyse the lining in different practical scenarios. To this end, a BIM-based approach is developed, which connects a user-friendly industry-standard BIM software with effective simulation tools for high-performance computing. A fully automatized design-through-analysis workflow solution for segmented tunnel lining is developed based on a fully parametric design model and an isogeometric analysis software, connected through an interface implemented with a Revit plugin. The IGA-Revit interface implements a reconstruction algorithm based on sweeping teachnique to construct trivariate NURBS lining segment geometry, which avoids the burden to deal with trimmed geometries.     

公路隧道喷射混凝土套拱加固结构力学特性

为研究喷射混凝土套拱加固前后二次衬砌与混凝土套拱的受力状况,依托陕西汉中至留坝段八里关隧道,运用有限元软件建立隧道混凝土结构套拱加固分析模型,并通过现场监测获取二次衬砌与套拱间的接触压力、套拱格栅拱架钢筋应力、套拱混凝土应力,将数值模拟结果与现场测试结果相结合,得出套拱结构的一般受力变化规律。结果表明:套拱加固前衬砌结构的最不利荷载位置位于施工缝附近的拱顶、拱肩与拱脚处; 由于衬砌局部变形与温度应力的影响,套拱混凝土应力变化呈现反复“上升-下降-上升”最后趋于稳定的特点; 套拱的作用是控制二次衬砌的进一步变形,套拱施作后所承受荷载较小,套拱反作用力远小于围岩作用于衬砌的应力,在应力计算中不应将衬砌与套拱作为整体计算; 套拱结构数值模拟所得的结果与现场测试套拱结构内力(轴力、弯矩)的大小及分布相似度高,但在衬砌裂损严重部位,数值模拟所得结果误差较大,应以现场测试结果为准。     

双层复合衬砌隧洞运行安全预警监控指标研究

双层复合衬砌结构是一种新型隧洞衬砌结构型式,其外衬承受外部水土压力,内衬承受内水压力,体现了"结构联合、功能独立"的新型输水隧洞设计理念,目前该衬砌型式已成功应用到我国北方某输水工程中,如何确定双层复合衬砌隧洞安全预警监控指标是工程运行管理的重点和难点。本文基于以往研究成果,提出了工程结构监控指标及监控阈值确定的统一技术路径;根据双层复合衬砌结构受力特点,开展可能破坏模式分析;基于破坏模式与监测量的敏感性分析,提出层间渗压作为双层复合衬砌隧洞结构核心监控指标,内衬处的钢筋计测值以及外衬处的测缝计测值作为辅助监控指标,为双层复合衬砌隧洞安全运行提供借鉴和参考。     

Analytical modeling of complex contact behavior between rock mass and lining structure

Based on the nondestructive test data of operating railway tunnels in China, this paper summarizes the basic characteristics of the complex contact behavior between the rock mass and lining structure. The contact modes are classified into dense contact, local non-contact, and loose contact. Subsequently, the corresponding mechanical model for each contact mode is developed according to its mechanical characteristics using the complex variable method. In the proposed mechanical model, a special algorithm is introduced to detect whether the local non-contact zone is re-contacted. Besides, a novel conformal mapping method is also proposed to accurately calculate the mechanical response of the concrete lining. Finally, the accuracy of the proposed method is verified by comparing it with the finite element method (FEM). Several parameter investigations are conducted to analyze the effects of different contact modes on the rock–lining interaction. The results show that: (i) the height of the local non-contact area does not have a significant effect on the contact stress distribution if no re-contact occurs; (ii) backfill grouting can reduce the local stress concentration caused by poor contact modes; and (iii) reducing the friction coefficient of the interface can lead to a more uniform distribution of internal forces in the concrete lining.     

几种不同衬层材料水润滑轴承的润滑特性分析

以船舶水润滑轴承为研究对象,建立水润滑轴承双向流固耦合模型,采用有限元法研究偏心率为0. 6时,赛龙、飞龙、丁腈橡胶和超高分子聚乙烯4种不同衬层材料水润滑轴承的润滑特性。研究结果表明:转速一定时,4种衬层材料沿轴向和周向的衬层变形分布较为一致,其中丁腈橡胶衬层的变形最大; 4种衬层材料沿轴向和周向的压力分布趋势也较为一致,最大的压力值均出现在210°～270°之间,同时在270°～30°之间水膜压力波动较大。4种衬层材料的摩擦因数均随转速的增大呈现先增大后减小的趋势,其中丁腈橡胶的摩擦因数最大,超高分子聚乙烯的摩擦因数最小。     

深厚表土层变断面钻井井壁竖向稳定临界深度的有限元计算

在给出了深厚表土层钻井井壁竖向稳定性有限元基本理论的基础上，结合工程实例，计算出该钻井井壁的竖向稳定临界深度为635 m（其钻井井壁全深为645.3 m），表明该钻井井壁在下沉到底时存在竖向失稳的可能性.通过增加横向约束的方法，井壁的竖向稳定性可得到有效地改善.同时研究了井壁的质量、井壁上下端的约束条件和井壁底接触面积等因素对钻井井壁竖向稳定临界深度的影响.结果表明：井壁的质量与钻井井壁竖向稳定临界深度成反比；井壁上下端的约束条件对井壁的竖向稳定性影响较大；井壁底与岩面的接触面积越大，井壁的竖向稳定性越强.     

金银火法冶炼中炉衬废砖选矿回收金银

金银火法冶炼中炉衬废砖的金银含量高，回收价值大。研究确定了浮－重联合选矿、产品酸浸除镁的炉衬废砖处理工艺。采用组合浮选药剂，可强化浮选效果，浮选尾矿经摇床重选确保了粗粒金银的回收；精矿酸浸除镁可满足冶炼要求；尾矿脱镁后可返回铅粗炼系统综合回收金、银、铜、铋等有价金属，有效地利用了资源。工艺流程简单、合理，易于实施，应用于生产取得了良好的经济效益     

喷射混凝土衬砌爆破损伤的数值分析

根据混凝土损伤的基本理论，把混凝土分段曲线损伤模型应用到喷射混凝土衬砌的有限元分析中。利用APDL语言编程对ANSYS进行二次开发．模拟了地下工程构建过程中，掘进爆破冲击波对喷射混凝土衬砌的损伤影响程度。实例计算考虑了不同条件下混凝土衬砌的最大损伤值及损伤积累发展趋势。按照5％的允许损伤准则，求出了不同条件下的最大炸药用量，为地下工程掘进施工提供了理论依据。