车用复合材料应用与开发关键浅析

随着我国新能源汽车销售量和保有量双双提升,先进复合材料作为轻量化效果最明显和可靠性最佳的轻量化材料之一,在新能源汽车轻量化进程中将扮演重要角色。汽车用复合材料随着汽车轻量化的推进和新能源汽车的迅猛发展得到了广泛的重视和应用,汽车用复合材料的开发和应用比例逐步提升,所以文章将结合车用复合材料的研究进展和情况,从整车开发和应用的角度探讨车用复合材料应用与开发关键。     

Through-wall yield ductile burst pressure of high-grade steel tube and casing with and without corroded defect

Service environment of tube and casing in deep and ultra-deep well is getting more and more complicated, and the internal pressure applied to tube and casing is higher, so that the high-grade steel tube and casing (HGTC) made of ductile material is widely used. Obviously, the calculation of ductile burst pressure for HGTC is one of the key factors in design and important to safe and efficient development of unconventional oil and gas resources. Here, based on the failure principle of through-wall yield and unified yield criterion, the unified formula of through-wall yield ductile burst pressure (TYBP) for tube and casing under practical service condition which can be used to calculate TYBP of API HGTC and non-API HGTC accurately and reasonably by using true material parameters, has been deduced in this paper with due consideration of the effect of Bauschinger effect (BE), material hardening and intermediate principal stress (IPS) on the TYBP, by which the influence rules of BE, IPS and yield criterion on TYBP of tube and casing have been investigated.（The effect of lattice effect (BE), material hardening and intermediate principal stress (IPS) on TYBP is accurately and reasonably derived from non-API HGTC by using real material parameters. The value of BE, IPS and the TYBP yield criterion of pipe and casing are studied. Eight kinds of classic through-wall yield ductile burst formulas for tube and casing made of new material have been be derived from a series of yield criterion, by which TYBP model of HGTC with and without corrosion defect has been established based on weighted twin shear stress yield criterion. The calculation results of TYBP model presented by this paper are the closest to the full-scale burst experimental data than the other burst models, which can provide an important reference for burst pressure design and estimation of HGTC in deep and ultra-deep well.     

Towards a unified methodology for the simulation of rupture in collision and grounding of ships

The aim of the work is the definition of a procedure for the numerical simulation of the response of ship structures under accidental loading conditions, which suffer various different modes of failure, such as tension, bending, tearing and crushing and in particular to investigate the effect of material modeling, i.e. material curve and rupture criterion as well as mesh size and strain rate effect on the results. To this end, different material models and simulation techniques were used for the simulation of eighteen indentation tests conducted by different research groups. The simulations were performed using the explicit finite element code ABAQUS 6.10-2. The tests refer to the quasi-static and dynamic transverse and in-plane loading of various thin walled structures which represent parts of a ship structure. Three rupture criteria are incorporated into VUMAT subroutine, which interacts with the explicit finite element code and refers to an isotropic hardening material that follows the J₂ flow theory assuming plane stress conditions, in order to investigate the prediction and propagation of rupture. The focus is on investigating whether it is possible to define a unified methodology, which is appropriate for the simulation of all different tests. Consistency in the numerical results is observed with the use of an equivalent plastic strain criterion, in which formulation a cutoff value for triaxialities below −1/3 is included.     

企业铁路智能运输调度平台的关键流程

企业铁路智能运输调度平台主要由调度计划管理子系统、计算机联锁子系统、调度集中控制子系统、调度监督子系统、物流自动跟踪子系统、机车无线作业信息子系统以及车号识别子系统构成,并与企业ERP系统通过运调接口服务器相联。调度作业计划在通过计算机网络传送给计算机联锁子系统的同时,通过集群无线传输方式传送给机车信息平台,进而传输给司机、调车员和连接员。在计算机联锁的基础上,根据机车运行的起始与目标地点,由智能运输调度平台按照特定的规则自动确定机车的行驶路径,预排进路,并经人工确认后,实现自动调度机车到达目的地。基于轨道电路和车号识别技术建立企业铁路物流自动跟踪子系统,根据作业计划,及时准确掌握站场内的存车信息以及同步反映货车所装载的货物信息。企业铁路智能运输调度平台于2004年8月在宝钢集团上海梅山钢铁公司成功投入使用。     

浅谈高速公路材料质量控制

介绍了公路常用材料的检验项目、频率和主要质量控制项目。通过预防、采取措施,达到监控目的,有效地控制了原材料的质量。     

WB36管道焊接的工艺试验研究

由于具有较高的综合机械性能，WB36钢已逐渐成为新型电站给水系统管道用钢的首选材料。按照国家相关焊接工艺评定规范的具体要求，选择了一种较新型的焊接材料，按照工艺设计，对这种高强度的低合金管道用钢进行了一系列的试验和分析，在焊接接头的各项性能满足要求后，证实了用于实际生产的可行性。     

不同特性材料在裂解连杆上应用的可行性研究

为探索连杆裂解工艺在不同连杆材料上应用的可行性,采用塑性有明显差异的几种材料,在特殊的应力槽加工工艺条件下进行了连杆裂解试验。结果表明:对于球铁和高碳微合金非调质钢,通过对断后试样加载以模拟连杆螺栓对分离面的压密过程,使分离面的变形充分弥合,断后变形量和分离面形貌均可满足连杆裂解工艺要求;对于非调质态中碳钢,在一定的裂解槽加工工艺条件下,断后变形量和分离面形貌也可满足连杆裂解工艺要求;而对于调质态中碳钢,在试验的工艺条件下,断后变形量和分离面形貌均无法满足连杆裂解工艺要求     

北京地铁十号线呼家楼站超前小导管注浆材料试验及注浆工艺

北京地铁十号线呼家楼站,主体结构开挖其拱部地层为粉细砂、圆砾、高含水量粘土,其自稳性差。通过水泥—水玻璃浆液、改性水玻璃浆液不同配比在不同地层止水、加固的试验应用及优化注浆工艺,提高了工效,确保了地面沉降的控制范围和施工安全。     

基于“4M1E”影响因素的敞开式TBM快速掘进保障措施

TBM施工是一个复杂的系统工程,涉及的专业多、领域广,需要各个制约因素的高效集成,充分确保TBM设备利用率,加快施工进度,是体现TBM优势的关键。将影响TBM施工的各项因素归结为"人、机、料、法、环"5个方面进行研究。结果表明,通过培养高素质的人员管理队伍、保障完好的设备状态加之对材料供应、施工方法、环境控制等方面的科学管理,能够发挥人员的主观能动性、降低施工风险、体现设备的先进性,使快速掘进得以实现。     

维他橡胶沥青黏结层在高速公路路面大修工程中的应用

高速公路大修工程采用罩面方案时,新铺面层与旧路面面层间的黏结状况是影响罩面路段路面综合使用性能的重要因素。基于维他橡胶沥青优异的黏结力和弹性变形能力,依托京沪高速公路沂淮江段罩面工程,分别从材料质量、施工工艺、质量控制等方面,分析探讨了维他橡胶沥青黏结层技术要点及其罩面工程中的应用情况,并通过后续观测对其性能进行了验证,结果表明:维他橡胶沥青黏结层在路面大修工程中具备较好的路用性能。研究结果可为类似工程提供参考借鉴。