CaPaSIM statement of methods

In the present paper, the method for calculation of the dynamic pantograph–catenary interaction developed by the Royal Institute of Technology and the Swedish National Rail/Road administration (Trafikverket) is described and the results of the benchmark exercise are discussed. The method is based on the commercial Finite Element software ANSYS. The geometry of the catenary and pantograph is defined in a pre-processor, BARTRAD, developed by Trafikverket, and is automatically translated into an ANSYS model. Basically all types of catenary systems could be handled as well as different types of non-linearity. There are both 2D and 3D versions of the code existing. The results achieved in this first stage of the benchmark are well in line with the results from the other partners in the benchmark study     

OSCAR statement of methods

OSCAR (Outil de Simulation du CAptage pour la Reconnaissance des défauts) is the pantograph–catenary dynamic software developed by Société Nationale des Chemins de fer Français (SNCF) since 2004. A three-dimensional finite element (FE) mesh allows the modelling of any catenary type: alternating current (AC) or direct current (DC) designs, and conventional or high-speed lines. It is a representative of the real overhead line geometry, with contact wire (CW) irregularities, staggered alignment of the CW, dropper spacing, wire tension, etc. Nonlinearities, such as slackening of droppers and unilateral contact between the pantograph and the CW, are taken into account. Several pantograph models can be used, with a complexity level growing from the three-lumped-mass model to the multibody model. In the second case, a cosimulation between the FE method catenary and the multibody pantograph models has been developed. Industrial features for pre- and post-treatments were developed to increase robustness of results and optimise computation time. Recent developments include volume meshing of the CW for stress computation or statistical analysis and lead to new fields of studies such as fatigue failure or design optimisation. OSCAR was fully validated against in-line measurements for its different AC and DC catenary models as well as its different pantograph models (with independent strips for instance) and has continuously been certified against EN50318 since 2008.     

CANDY statement of methods

This paper presents a detailed overview of CANDY, a catenary–pantograph dynamic interaction software. Authors describe the main key points of the formulation, focusing on its time-integration scheme, the pantograph and contact models as well as the solution of the initial equilibrium problem. Nonetheless one of the most important features of CANDY is its moving finite element mesh, which enables accurate results without excessive computational cost. The validation of the model against the European Standard EN 50318 and some conclusions and comments about the results of the benchmark are also included.     

SPOPS statement of methods

The Simulation Programme for Overhead contact lines – Pantograph System (SPOPS) is based on a two-dimensional finite element model of an overhead contact line and a lumped mass model for a pantograph. The SPOPS allows for a lateral change of contact points between the pantograph and the contact wire and for the rolling motions of contact strips in the pantograph model. Thus, the programme can consider the stagger of a contact wire in a dynamic simulation. Either a penalty method or a Lagrange multiplier method can be chosen to model the contact phenomenon between a pantograph and a contact wire. According to pantograph–catenary benchmark results, the simulation results obtained from the SPOPS are very close to the average values of the simulation results obtained from programmes implemented in the benchmark work in all cases, including a three-dimensional (3-D) case. These benchmark results demonstrate that the SPOPS is as accurate as other fully 3-D simulation programmes while utilising minimal computational efforts.     

PACDIN statement of methods

PAntograph–Catenary Dynamic Interaction (PACDIN) is a code developed by the vehicle technology research centre (CITV) of the Universitat Politècnica de València in collaboration with the railway company Talgo S.L. The model of the catenary is a finite element model using absolute nodal coordinates. It is based on a general formulation that can be applied for analysing a wide range of catenary configurations, including stitch wire, transitions or non-straight path tracks. The formulation is fully non-linear and includes large deformations, dropper slackening and contact interaction. The model is linearised when deformations are small, as in the case of the benchmark dynamic analysis. The results of the PACDIN code show a good agreement with the average results of other benchmark codes.     

石砌U型高桥台破坏机理及加固改进对策研究

石砌U型高桥台是西部山区公路建设中广泛采用的结构形式,也是一个受力复杂的砌体结构,在填土荷载和车辆荷载作用下经常发生局部开裂破坏,其破坏机理尚不清楚,为了研究其破坏机理并解决局部开裂破坏问题,本文采用常规U型桥台及钢筋混凝土圈梁及倒角加固改进后的10∶1模型进行试验研究,并进行了三维有限元分析。通过试验及计算结果,基本摸清了其破坏机理,并验证所采用的改进方法简单可靠。     

初应力法模拟隧道开挖过程的有限元原理及列式

阐述有限元方法模拟隧道开挖过程的理论和公式,提出分析中的若干基本概念和问题,描述采用ANSYS软件模拟开挖的原理和步骤。通过算例说明模拟分析的有效性。     

<TPL-PCRUN> Statement of methods

TPL-PCRUN is a software program for the dynamic interaction simulation of pantograph–catenary systems. In the benchmark, based on the finite element method, the catenary model was built and the pantograph was considered as a three-level spring–damper–mass system. Then, through the contact definition between pantograph and catenary, the coupled model of the pantograph and catenary system was established. The respective dynamic equations of motions were solved by the time integration method. Thus, the simulation results were obtained and submitted for the comparison with the other software. On the other hand, a standard model from EN50318 was established and analysed by TPL-PCRUN. The simulation results by TPL-PCRUN were remarkably consistent with the reference values given by EN50318. It was proved that the results by TPL-PCRUN can be reliable. Recently, the software has been updated and improved. Some new models and algorithms are proposed, including the rigid–flexible hybrid pantograph model, contact definition considering appearance characteristics of the contact surfaces, a fluid–solid coupling algorithm of the pantograph and catenary system, etc.     

PantoCat statement of method

The pantograph–catenary dynamic interaction analysis program (PantoCat) addresses the need for a dynamic analysis code able to analyse models of the complete overhead energy collecting systems that include all mechanical details of the pantographs and the complete topology and structural details of the catenary. PantoCat is a code based on the finite element method, for the catenary, and multibody dynamics methods, for the pantograph, integrated via a co-simulation procedure. A contact model based on a penalty formulation is selected to represent the pantograph–catenary interaction. PantoCat enables models of catenaries with multiple sections, including their overlap, the operation of multiple pantographs and the use of any complex loading of the catenary or pantograph mechanical elements including aerodynamic effects. The models of the pantograph and catenary are fully spatial being simulated in tangential or curved tracks, with or without irregularities and perturbations. User-friendly interfaces facilitate the construction of the models while the post-processing facilities provide all quantities of interest of the system response according to the norms and industrial requirements.     

某道路沉降段路面有限元研究

将Abaqus有限元技术与道路沉降相结合,并根据张家口地区新建道路的现场监测试验数据以及当地地质环境条件,建立道路沉降有限元模型。数值模拟法试验表明,道路实际沉降值在检测完毕后,沉降为3.196~5.544 mm,而Abaqus有限元模拟得出的道路沉降值为2.229~4.135 mm,二者差距并不大。以此验证了Abaqus有限元模拟道路沉降技术在实际工程中的适用性。     

贝尔隧道与滑坡相互作用机理及加固方案

根据贝尔隧道实际工程概况,基于隧道与滑坡的相互作用机理研究,分析贝尔隧道与西尔瓜子滑坡的位置关系及水库、隧道和滑坡三者之间的联系,得出贝尔隧道与水库滑坡的相互作用机理及产生的原因。将隧道简化为合理的结构力学模型,并针对贝尔隧道提出合理的加固方案,对滑坡隧道进行理论分析,再结合数值模拟得到的结果,进一步分析了贝尔隧道与滑坡两者之间的关系及加固效果。     

水闸坞式结构的计算及数值模拟

坞式结构整体工程安全性的结构分析通过常规计算手段已经较为成熟,但缺乏综合所有外界条件对其中特殊节点的详细影响分析。为此采用Sap2000系列软件对坞式结构进行整体三维计算和二维简化计算,并与常规计算手段进行对比验证,以便为日后通过有限元方法有效分析该结构做准备。     

某黄土滑坡破坏机理数值研究

为了研究某黄土滑坡破坏的作用机理,运用有限元软件建立了三维有限元数值模型,分析了滑体和滑床之间的相互作用,研究了滑坡体破坏与加载变化影响因素的关系,并总结了在这些复杂因素下滑坡体应力变化规律。结果表明:在加载过程中,随着滑体的变形及拉裂,滑坡体的应力有从上部集中到整体分散的规律,当加载到一定程度时,滑体与滑床在顶端出现拉裂,进而沿着接触面迅速分离,滑坡的变形也从滑体的局部变形转变到滑体的整体失稳。数值模拟的结果与工程经验基本一致。     

液压挖掘机动臂的有限元分析

用Pro/E软件建立了液压挖掘机动臂的三维模型,对铰销间接触载荷的处理时采用经典弹性力学方法,选用板壳单元建立了动臂的有限元模型。对动臂的两种工况进行了计算,结合工作装置的静强度试验结果,进行对比分析,对现行设计提出了改进建议。     

分期堆载预压法加固料场软基一分期阶段的数值模拟

利用有限元软件对一分期堆载预压法加固的软基进行了数值模拟,预估了一级堆载的高度,分析了软基土体由于堆载而产生的初始破坏部位、塑性变形区域、位移沉降、应力、应变等,据此指导后期堆载过程中的监测,确保地基的稳定和堆载的安全。     

基坑开挖对紧邻建筑物沉降影响的数值分析

该文介绍了采用数值模拟方法对某地道工程基坑对临近建筑物的影响进行的分析。通过有限元模型,分析了南地道开挖过程对紧邻建筑物沉降的影响,并与监测数据对比。结果表明此方法计算值与监测值基本吻合,可以较好地模拟基坑紧邻建筑物的沉降规律。最后用此方法预测了北地道开挖对紧邻基坑北侧建筑物沉降的影响,对北地道工程施工有一定指导意义。     

斜向预应力混凝土路面数值模拟

为研究斜向施加预应力路面的受力特性,通过理论推导由斜向预应力产生的路面板内压应力计算公式,预应力筋的直径、布设角度和间距是影响板内应力的主要因素。建立力学模型,模拟分析预应力筋作用位置、布设间距和角度以及直径大小对路面板应力的影响,结果表明,斜向预应力混凝土路面的锚固区和板角部分区域出现拉应力,但混凝土不会出现开裂;预应力筋布置在1/2板厚偏下是合理的,此时板底压应力大于板顶部,路面板产生负弯矩;预应力布设角度建议范围为25＆#176;～45＆#176;;考虑到经济性和预应力筋张拉空间,建议预应力筋布设间距最小为0．5 m,预应力筋的布设间距也不能过大,过大易造成路面板应力分布不均匀;可通过调整预应力筋的直径,以得到合理的布设角度和间距。     

On the interest of integrating vehicle dynamics for the ground propagation of vibrations: the case of urban railway traffic

This paper presents a complete numerical model for studying the vertical dynamics of the vehicle/track interaction and its impact on the surrounding soil, with the emphasis on vehicle modelling. A decoupling between the track and the soil is proposed, due to the difficulty of considering all the subsystem components. The train/track model is based on a multibody model (for the vehicle) and a finite element model (for the track). The soil is modelled using an infinite/finite element approach. Simulations of both models are carried out in the time domain, which is better able to simulate the propagation of the vibration waves and to take into account the possible nonlinearity of a component. The methodology is applied in the case of an urban tram track and validated with the available experimental data. Models for the tram, the track and the soil are described. Results from the complete model of the vehicle and a simple model, based on an axle load, are compared with experimental results and the benefits of a complete model in the simulation of the ground vibration propagation induced by railway vehicles are demonstrated. Moreover, a parametric study of the vehicle wheel type is conducted, which shows the advantage of a resilient wheel, for various rail defects.     

大跨隧道临时支护拆除及二次衬砌施工数值模拟分析

对广州地铁区庄站浅埋暗挖大跨隧道采用荷载结构法,运用大型通用有限元分析软件ANSYS模拟隧道拆除支撑及2次衬砌施工的动态力学过程,分析研究施工过程各施工步序2次衬砌和初期支护内力、位移变化规律及隧道各施工阶段的施工安全状态,为该隧道设计施工提供科学依据。     

软土路基土工隔栅加筋作用机理研究

该文通过运用ANSYS有限元分析软件对软土路基土工格栅加筋的作用机理进行了数值模拟,研究了土工格栅加筋对软土地基应力场和位移场分布的影响。从计算结果分析可知,土工格栅堤底加筋对约束浅部地基土水平位移有显著作用,使最大水平位移点移向地基深处,使堤趾水平位移大幅减小,同时对竖向沉降有一定的均衡作用,加筋增强了路堤的整体性和稳定性,对地基承载力的提高也有一定作用。特别是加筋前后地表最大水平位移点的移位,对路堤填筑施工监测有一定借鉴意义。