Analysis and optimization of stamping and forming process of bearing outer ring

To address the common issues of wrinkling,tearing,and uneven wall thickness in the actual sheet metal stamp-ing process of the outer ring of needle roller bearings,this study analyzes critical technical indicators such asforming limits,thickness distribution,and principal strains in the forming process in detail.Three-dimensionalmodels of the concave and convex dies were constructed.The effects of different process parameters,includingstamping speed,edge pressure,sheet metal thickness,and friction coefficient,on the quality of the forming partswere investigated by varying these parameters.Subsequently,the orthogonal experimental method was used todetermine an optimal experimental group from multiple sets of experiments.It was found that under the processparameters of a stamping speed of 3000 mm/s,edge pressure of 2000 N,sheet metal thickness of 0.9 mm,andfriction coefficient of 0.125,the forming quality of the outer ring of the bearing is ideal.

郑州“7·20”地铁水淹事件STAMP致因分析

为探讨河南郑州“7·20”地铁5号线伤亡事件致因,综合运用系统理论事件模型与过程(STAMP)模型,分析5号线伤亡事件安全控制结构,据此逐级辨识事件致因;基于复杂网络理论将事件致因及其联系抽象为网络的节点和边,建立地铁水灾事件网络;计算聚类系数、度数等拓扑参数定量分析事件致因性质,确定关键致因。结果表明:地方党委政府面对汛情的应对部署不紧不实,缺少有效的组织动员和有关部门对工程建设存在失管失察是事件的深层根源;建设单位、设计单位等五方主体单位及运维单位的主体责任失职是事件的主观关键致因;应从政府及有关部门、五方主体单位和运维单位方面采取多元协同的风险防控措施。

采用STAMP-24Model的多组织事故分析

安全生产事故往往由多组织交互、多因素耦合造成,事故原因涉及多个组织。为预防和遏制多组织生产安全事故的发生,基于系统理论事故建模与过程模型(Systems-Theory Accident Modeling and Process,STAMP)、24Model,构建一种用于多组织事故分析的方法,并以青岛石油爆炸事故为例进行事故原因分析。结果显示:STAMP-24Model可以分组织,分层次且有效、全面、详细地分析涉及多个组织的事故原因,探究多组织之间的交互关系;对事故进行动态演化分析,可得到各组织不安全动作耦合关系与形成的事故失效链及管控失效路径,进而为预防多组织事故提供思路和参考。

基于STAMP-偏序集的非煤矿山爆炸事故系统风险评估模型

通过提出一种基于STAMP偏序集的系统性风险评估模型,揭示非煤矿山爆炸事故的发生机理,并为爆炸事故的有效预防和控制提供参考。首先,利用STAMP模型构建了非煤矿山爆炸事故的系统层次结构,确定了事件集及其层次关系,并从系统设计和安全控制的角度分析了事故的致因因素;然后,采用排序质心法计算了事件集的初始概率,并将概率矩阵作为偏序集评价模型的输入,得到了因素间的聚类关系和节点脆弱性;最后,通过一个实例验证了该模型的有效性和可行性。该模型能够图形化地描述各致因因素间的聚类关系、节点重要度以及系统各组件间的关系,从而能够有效识别系统的脆弱性节点,并为爆炸事故预防提供科学合理的控制措施。

Experimental research and application of cold cutting to hot stamping parts based on multiphase microstructure

Among the bottlenecks that hinder the improvement of the production efficiency of hot stamping are high strength and difficulty in edge cutting and hole punching.Starting from the preparation of hot stamping multiphase microstructure materials,this paper developed a plate quenching die system with controllable surface temperature and prepared four types of hot stamping plates with different martensite volume fractions.Then,straight edge cold cutting experiments were performed to study the influence of cutting clearance and cutting force on fracture quality.The results show that the bright zone is the largest when the cutting clearance is 0.14 mm,and the cutting experience coefficient of the hot stamping sheet with each martensite volume fraction is obtained when the cutting clearance is 0.14 mm.The research results of this paper were applied to the production of hot stamping parts.

基于STAMP与模型检验的全自动无人驾驶复杂运营场景安全验证方法

与传统列控系统相比,全自动无人驾驶运营场景更加复杂多变,潜在的危险及致因具有更强的隐蔽性和复杂性,给运营安全带来了新的挑战。针对以上问题,提出一种STAMP(Systems-Theoretic Accident Model and Process)与模型检验相结合的复杂运营场景安全验证方法。首先,基于STAMP理论构建运营场景分层控制结构模型,辨识潜在的不安全控制行为、分析危险致因和安全约束;其次,定义分层控制结构模型与安全状态机模型间的基本转换规则,基于分层控制结构模型、安全约束和转换规则,构建运营场景安全状态机模型;最后,针对提取的安全约束,利用数据流图建立安全属性验证模型,结合模型检验技术,对运营场景安全状态机模型进行形式化验证。以全自动无人驾驶运营场景中列车自动进站停车为例,对方法进行验证分析。结果表明,当STAMP理论提取的安全约束通过了场景安全状态机模型的验证时,表示在该场景中对应的不安全控制行为没有发生且不导致相应危险。该方法结合系统安全分析与形式化建模验证的优势,降低了运营场景建模的难度,构建的运营场景形式化模型满足系统安全约束,可以作为全自动无人驾驶系统安全设计和安全改进的重要基础。

Residual Stresses and Forming Quality of Metal Bipolar Plates for PEMFC During the Stamping Process

Stamping is a critical step in the manufacture of metallic bipolar plates.Typically,residual stress and a spring back effect appear on the bipolar plate after the stamping process,which impacts on the performance and lifetime of the proton exchange membrane fuel cell(PEMFC).The residual stress and spring back behavior which occur as a result of stamping a bipolar plate are investigated in this study.The effects of the punch radius,the die radius,the channel depth,and the clearance between the punch and the die on the residual stress and forming quality of the bipolar plate are examined.The stamping process can be divided into three stages.The high stress area and the middle section residual stress area were selected to study the formation process and to obtain the composition of the residual stress regions.Spring back was mainly related to the position of the fixed end of the sheet and the degree of plastic deformation,and the sheet thickness have increased by 2μm after spring back.Based on the results of finite element analysis,as described by the distribution of residual stress,the formation,the thickness of the middle cross section and the equivalent plastic strain,it was found that all the tool parameters affected the distribution of the residual stress.This research can provide a design reference for the manufacture of metallic bipolar plates based on the stamping process.

Application of new generation low-strength hot stamping steel to improve the crash performance of BIW

With the improvement of safety performance,car parts have different requirements for material strength and energy absorption performance.The conventional 1500-MPa hot stamping steel cannot well meet the requirements.Considering the new generation 600-MPa hot stamping steel,this study investigates the applicable car parts and hot stamping process,then designs a new body-in-white(BIW)crash test for obtaining the crash performance of the new material.Through the actual part development and crash test,it is verified that the application of the new generation hot stamping steel can improve the crash performance of BIW.

基于StaMPS-PS时序InSAR对流层延迟改正方法评估

时序分析是合成孔径雷达干涉测量(InSAR)的一项关键技术,它被广泛应用于监测广阔地区的地表缓慢形变。这种方法能够提供大范围、大面积的形变监测。其中,StaMPS PS方法凭借适用范围广、开源等优点,受到众多学者的使用。但在时序InSAR中,对流层延迟相位会导致形变监测精度的降低,因此,以合肥市为研究区域,分析了经验模型线性改正、GACOS(generic atmospheric correction online service for InSAR)改正和欧洲中期天气预报中心(ECMWF)最新发布的ERA5数据集改正,并对比这3种方法在时序InSAR反演形变速率中的改正效果。通过计算得到研究区的标准差,进行比较分析和验证。其中线性改正、ERA5和GACOS改正后的标准差分别降低了21.71%、16.14%、10.38%。对于合肥区域,这3种方法均可减弱对流层延迟的影响,且精度都有所提高,其中线性改正效果最好,适用性更高,ERA5和GACOS受天气以及地面监测点密度等影响,在该区域改正效果较差。

A STAMP-Game model for accident analysis in oil and gas industry

Accidents in engineered systems are usually generated by complex socio-technical factors.It is beneficial to investigate the increasing complexity and coupling of these factors from the perspective of system safety.Based on system and control theories,System-Theoretic Accident Model and Processes(STAMP)is a widely recognized approach for accident analysis.In this paper,we propose a STAMP-Game model to analyze accidents in oil and gas storage and transportation systems.Stakeholders in accident analysis by STAMP can be regarded as players of a game.Game theory can,thus,be adopted in accident analysis to depict the competition and cooperation between stakeholders.Subsequently,we established a game model to study the strategies of both supervisory and supervised entities.The obtained results demonstrate that the proposed game model allows for identifying the effectiveness deficiency of the supervisory entity,and the safety and protection altitudes of the supervised entity.The STAMP-Game model can generate quantitative parameters for supporting the behavior and strategy selections of the supervisory and supervised entities.The quantitative data obtained can be used to guide the safety improvement,to reduce the costs of safety regulation violation and accident risk.

The Use of Hand Stamps in the Manuscript Maps Drawn by East Asian Countries in the Eighteenth and Nineteenth Centuries

It was generally accepted that manuscript maps,as distinct from printed maps,exhibited no signs of printing and were entirely hand-drawn.Western scholars Christopher Terrell and Tony Campbell were the first to break this stereotype in 1987,followed by Catherine Delano-Smith and Chet Van Duzer who discovered a few Renaissance maps and two Qing dynasty maps that showed use of hand stamps.Inspired by these findings,this paper explores the stamped map signs in ten Chinese maps,three Japanese maps,and three Korean maps.By analyzing each map and each type of stamp,this paper provides more examples of this research,broadens the research horizons and geographical area,and demonstrates that use of stamps in manuscript maps was invented independently among people of different regions and civilizations as a result of human nature.

基于IRML-STAMP的舰船加油系统风险因素识别方法

为研究舰船加油系统遭受外界干扰后的系统功能状态变化情况和系统自身恢复能力,基于IRML-STAMP方法对舰船加油系统风险因素进行识别,定量评估舰船加油系统动态弹性,并与基于传统STAMP方法的评估结果进行比较。结果表明:利用基于IRML-STAMP的舰船加油系统风险因素识别方法可以精确找出失效后导致舰船加油系统动态弹性损失最多的STAMP模型的关键节点;以舰船加油系统加油作业设定故障场景为例,压力表等仪表是该系统的关键节点,压力表等仪表故障中断后,系统动态弹性大幅下降0.161;当故障传播路径中不包含关键节点时,系统动态弹性最大,当干扰出现在关键节点时,系统动态弹性最小,差值为0.101;与传统STAMP方法相比,IRML-STAMP方法评估结果可以准确定位系统风险,提高系统动态弹性。该研究结果可以帮助提高舰船加油系统的抗干扰性,对现场舰船加油系统的风险因素识别具有指导意义。

基于板料冲压成形仿真系统FASTAMP-NX10与冲压模具智能设计系统SIS-V2.0的拉伸模设计

以电子产品金属外壳为实例,具体分析了其成形特点,找出某电子产品金属外壳冲压件成形的共性。介绍了电子产品金属外壳的成形特点和外壳件冲压模具设计的基本原则,其中包括了冲压方向、工艺补充面等设计的常用手法。直接用工业三维软件NX10.0构造出外壳冲压模具的三维实体模型,完成了电子产品金属外壳的模具设计,更真实的反映了模具零件之间的装配关系,减少了实际模具设计带来的一些问题和制造时间。同时,模具各部分的干涉检查能够方便地做到,从而提高了电子产品面壳模具结构的设计效率和质量,缩短了模具的设计和制造时间,这对制造业尤其是模具的制造来说尤为重要。

Forming defects in aluminum alloy hot stamping of side-door impact beam

The forming defects, including thinning, rupture, wrinkling and springback, usually arising in producing a side-door impact beam, were investigated by trial and numerical simulation. A temperature-related constitutive model specific to the temperature range from 350 °C to 500 °C was established and used for the numerical simulation. The trial and numerical simulation were conducted to clarify the quantitative characteristics of forming defects and to analyze the effects of process parameters on the forming defects. Results show that the rupture situation is ameliorated and the springback is eliminated in the aluminum alloy hot stamping. The wrinkling severity decreases with increasing blank holder force (BHF), but the BHF greater than 15 kN causes the rupture at the deepest drawing position of workpiece. The forming defects are avoided with lubricant in the feasible ranges of process parameters: the BHF of 3 to 5 kN and the stamping speed of 50 to 200 mm/s.

Formability of aluminum-silicon coated boron steel in hot stamping process

Flow behavior of the Al-Si coated boron steel was investigated with Gleeble-3500,in comparison with the uncoated one.Effect of deformation conditions on the coating integrity was characterized by optical microscopy.Facture surfaces of the coated steels were inspected under SEM.Experimental results indicate that the ultimate tensile strength and ductility of the Al-Si coated boron steel are lower than those of the uncoated steel under test conditions.Extensive cracks occur in the coating after tensile tests;the width and density of cracks are sensitive to the deformation temperatures and strain rates.The bare substrate exposed between the separate coating segments is oxidized.Appearance of the oxide degrades the Al-Si coating adhesion.Remarkable difference between formability of the coating layer and the substrate is confirmed.The formability of the Al-Si coating could be optimized by controlling the phase transformation of the ductile Fe-rich intermetallic compounds within it during the austenization.

Experimental and simulation research on thermal stamping of carbon fiber composite sheet

To improve the manufacture efficiency and promote the application of composites in the automobile industry, a new composite forming method, thermal stamping, was discussed to form composite parts directly. Experiments on two typical stamping processes, thermal bending and thermal deep drawing, were conducted to investigate the forming behavior of composite sheets and analyze the influence of forming temperature on the formed composite part. Experimental results show that the locking angle for woven composite is about 30°. The bending load is smaller than 5 N in the stamping process and decreases with the increase of temperature. The optimal temperature to form the carbon fiber composite is 170 ℃. The die temperature distribution and the deformation of composite sheet were simulated by FEA software ABAQUS. To investigate the fiber movement of carbon woven fabric during stamping, the two-node three-dimension linear Truss unit T2D3 was chosen as the fiber element. The simulation results have a good agreement to the experimental results.

基于STAMP的社区燃气管道事故应急疏散过程中安全隐患识别方法

燃气作为一种高效能源已得到迅速普及,燃气管网敷设走进千家万户,但社区燃气管道事故时有发生,给人民的生命和财产造成危害。为对社区燃气管道事故发生后应急疏散过程中存在的安全隐患进行识别,通过对社区燃气管道事故应急疏散过程进行分析,提出一种基于系统理论事故模型及过程(STAMP)方法的社区燃气管道事故应急疏散过程中安全隐患的识别方法,该方法按照明确社区燃气管道事故应急疏散过程及影响因素、分析系统事故安全性、识别系统安全约束、确定安全控制结构、识别潜在控制缺陷和安全隐患5个步骤识别社区燃气管道事故应急疏散过程中的安全隐患,并通过对北京市不同类型的社区和历史事故案例的调研,利用该方法对不同类型社区燃气管道事故应急疏散过程中存在的安全隐患进行了识别。结果表明:老旧社区安全隐患主要与设施不齐全、装置老旧、居民年龄偏高有关;新型商品住宅区安全隐患主要为高层疏散困难、人口密度偏大;历史事故案例中社区燃气管道事故应急疏散过程的安全隐患主要为爆炸产生的冲击波严重、事故发生时间正值假期清晨人口密度偏大。

STAMP框架下化学品船智能液货系统风险分析

为分析化学品船智能液货系统的安全性,采用系统理论事故模型与过程(System-Theoretic Accident Model and Processes, STAMP)方法,构建了化学品船智能液货系统控制反馈模型;基于系统理论过程分析(System-Theoretic Process Analysis, STPA),确定系统级事故,识别不安全控制行为并分析不安全控制行为关键致因;将不安全控制行为作为风险因素,利用三角模糊数对不安全控制行为风险进行量化。结果表明,26种不安全控制行为中,泵管阀动态调节、人员监测、数据采集、货品相容性判定等因素对风险影响程度较高。该分析结果可为化学品船智能液货系统的应用和安全管理提供参考。

基于STAMP-DEMATEL的既有建筑改造安全事故致因研究

城市更新背景下既有建筑改造将是大势所趋,而既有建筑改造安全事故逐年增多,危害到国家、企业和个人生命财产安全。厘清既有建筑改造安全事故的致因并针对性防范,对降低安全事故的发生频率具有重要现实意义。基于STAMP模型,分析并构建既有建筑改造项目安全事故的分层控制结构,并以此为框架识别和筛选事故致因因素;运用DEMATEL算法分析安全事故系统各层级致因因素之间的关联关系,辨识关键性致因因素;以泉州XJ酒店改造工程坍塌事故开展案例研究,验证STAMP-DEMATEL模型的适用性。结果表明:既有建筑改造项目分层控制结构包括物理层、现场基础层、运营层、政府及社会层等4个递进层级;政府社会层如五方责任主体监督监管失察、既有建筑改造施工标准体系不健全、企业行为规范缺失等原因因素属于导致既有建筑改造事故发生的高效力因素;物理层、基层如钢柱板件严重变形、应急预案缺失、改造技术方案安全性缺失、施工机械选择不当等结果因素属于诱发事故的直接因素;基于STAMP和DEMATEL的分析结果与案例事故报告高度贴合。所构建的安全事故致因模型可用于指导既有建筑改造施工安全管理。

Prediction and Control of Wrinkle and Fracture for Stamping Regular Polygonal Box

Based on the deformation characteristic of regular polygonal box stamped parts and the superfluous triangle material wrinkle model,the criterion of regular polygonal box stamped parts without wrinkle was deduced and used to predict and control the wrinkle limit.According to the fracture model,the criterion of regular polygonal box stamped parts without fracture was deduced and used to predict and control the fracture limit.Combining the criterion for stamping without wrinkle with that without fracture,the stamping criterion of regular polygonal box stamped parts was obtained to predict and control the stamping limit.Taken the stainless steel0Cr18Ni9(SUS304)sheet and the square box stamped part as examples,the limit diagram was given to predict and control the wrinkle,fracture and stamping limits.It is suitable for the deep drawing without flange,the deep drawing and stretching combined forming with flange and the rigid punch stretching of plane blank.The limit deep-drawing coefficient and the minimum deep-drawing coefficient can be determined,and the appropriate BHF(blank holder force)and the deep-drawing force can be chosen.These provide a reference for the technology planning,the die and mold design and the equipment determination,and a new criterion evaluating sheet stamping formability,which predicts and controls the stamping process,can be applied to the deep drawing under constant or variable BHF conditions.