Development of a Side Door Composite Impact Beam for the Automotive Industry

The automobile industry has been searching for vehicles that use less energy and emit fewer pollutants, which has resulted in a high demand for fuel-efficient vehicles. Because of their higher strength-to-weight ratio compared to traditional steel, using fiber-reinforcement composite materials in automobile bodies has emerged as the most effective strategy for improving fuel efficiency while maintaining safety standards. This research paper examined the utilization of fiber-reinforced composite materials in car bodies to meet the increasing consumer demand for fuel-efficient and eco-friendly vehicles. It particularly focused on a carbon-aramid fiber-reinforced composite impact beam for passenger car side door impact protection. Despite the encouraging prospects of the carbon-aramid fiber-reinforced beam, the research uncovered substantial defects in the fabrication process, resulting in diminished load-bearing capacity and energy absorption. As a result, the beam was un-successful in three-point bending tests. This was accomplished by using an I cross-section design with varying thickness because of the higher area moment of inertia. Vacuum-assisted resin transfer molding (VARTM) manufacturing process was used and the finished beam underwent to three-point bending tests.

Simulation Analysis of Electromechanical Coupling for Unmanned Aerial Vehicle Cabin Door System

In order to study the dynamic response of the unmanned aerial vehicle cabin door opening and closing system under impact load conditions, considering the flexible treatment of mechanical components, and the system’s motion with different stiffness of energy-absorbing components, a rigid-flexible coupling model of the cabin door actuation system was established in LMS. Virtual. Motion. In Amesim, a control model of the motor was created. Through the Motion-Amesim co-simulation module, the dynamic module of the system was combined with the motor control module to complete the electromechanical coupling simulation and analyze the results. .

基于DOORS和Eclipse的软件追溯链审查方法研究

在高安全软件开发过程中,软件追溯链审查是提高软件质量的重要手段。为了解决基线管理、审查完整性和结果可复用等问题,提出了一种基于DOORS平台和Eclipse平台的软件追溯链审查方法。为审查活动设计并开发了工具软件,采用差异比对算法进行版本迭代后的审查结果复用。经实际应用,该方法可以提高软件追溯链审查的效率及效果。

Hot Door CADtools绘制产品立面图和轴测图的分析及实践

矢量软件在绘制产品及工程视图时会出现数据不够准确,参数化控制偏弱等情况,另一方面专业的CAD制图软件又让普通设计师难以下手。基于Adobe Illustrator平台上的Hot Door CADtools插件在这些的问题中找到了平衡点,它能既能够像专业的CAD软件一样为图形标注提供准确的尺寸,同时又让CAD制图变得亲切和富有人性化。

一种基于DOORS的软件需求开发过程优化方法

需求过程是整个软件生存周期中非常重要的一个阶段。因为需求开发过程和需求管理过程的差异,需求开发工具和需求管理工具的选择也可能不同。由此需要将软件需求从需求文档录入至专业需求管理工具的数据库。对此,提出一种基于DOORS的软件需求开发过程优化方法,定义需求文档的编制格式,并开发基于DXL脚本语言的转换插件,最后方便地将RTF格式的需求文档导入至DOORS数据库,能够快速有效地实现需求开发和需求管理之间的衔接。

Service Adaptable 3G Turbo Decoder for Indoor/Low Range Outdoor Environment

For the well-known 3G mobile communications standard UMTS, four different service classes have been specified. Considering two turbo decoding algorithms, like SOVA and log-MAP, it would be desirable to use an efficient turbo decoder. In this paper this decoder is shown to adapt dynamically to different service scenarios, considering parameters like performance and complexity for indoor/low range outdoor operating en-vironment. The scenarios show that for streaming service class real-time class applications the proposed de-coding algorithm depends on data rate;for the majority of scenarios SOVA is proposed, whereas log-MAP is optimal for increased data rates and medium-sized frames. On the other hand, conversational service class real-time applications cannot be established. For the majority of non real-time applications (interactive and background service classes) either algorithm can be used, while log-MAP is proposed for medium data rates and frame lengths.

基于Doors工具的系统需求三维模型

作为设计的本质,需求在飞机的研制过程中一直贯穿始终,并以树状从上至下逐步展开。从飞机研制到航电分系统研制,再到设备级研制,需求数量呈指数级展开,同时需求属性也更加复杂多样,以确保设计在分解和追随过程中完整、准确地展开,这就导致了需求在研制和变更过程中存在一定的复杂性和管理困难。为能从设计和逻辑上更有效地描述需求的生命周期和传递过程,设计了一套基于Doors工具的需求三维建模方法,将复杂的需求过程更形象地描述清楚,有效帮助系统功能和产品的实现。

基于DOORS的软件需求开发与管理

对于软件而言,其整个生存周期内最为关键的环节便是需求过程,但需求开发及管理过程各异,因此,实践中需要选取差异化的工具,以此将软件需求由需求文档转录到需求管理数据库。本文提出了基于DOORS的软件需求开发与管理,旨在有效衔接需求开发与管理。

运用Solaris门(Door)技术对提高计算机内存利用率的影响

门(Door)技术是Sun公司开发的Solaris操作系统中的一个进程间通信的功能.通过分析门(Door)机制的基本原理和结构,编写了基于Solaris门(Door)机制的客户/服务器的测试程序,并利用Solaris操作系统提供的内核分析工具对计算机内存的使用情况进行了详细的分析,获得了确定的结果.实现了在门(Door)机制的结构下对内存的共享,提高了内存的利用率,并且对于相同并发线程数量与利用率的关系给出了分析与结论.

Magnetic field and performance analysis of a tubular permanent magnet linear synchronous motor applied in elevator door system

A novel elevator door driven by tubular permanent magnet linear synchronous motor (TPMLSM) is presented. This TPMLSM applies axial magnet array topology of the secondary rod, air-cored armature windings and slotless structure of the forcer to improve the stability of the thrust. The influence of two major dimensions, the pitch and radius of the permanent magnet (PM), on magnetic field was studied and the best values were given by the finite element analysis (FEA). The magnetic field, back EMF and thrust of the motor were analyzed and the PM size was optimized to reduce the harmonic components of the magnetic field and improve the performance of the motor. Predicted results are validated by the experiment. It is shown that the performance of the motor and the novel elevator door system is satisfying.

DOORS在FADEC系统需求确认中的应用研究

需求获取及确认是需求分析过程中最重要的活动。为解决传统需求确认方式在人力及资源成本过高、过程不够显形等方面问题,提出了一种使用DOORS需求管理工具提供的讨论交流机制进行需求的获取及确认的方法。方法不但继承了传统确认方式的有效性,又节约了成本,在状态显形、可追踪性方面优势显著,并将方法应用于航空发动机FADEC系统,大大提高了需求确认的效率和效果。方法实用性和通用性极强,可推广至其他行业的需求获取及确认过程中。

改良Swing-door技术钩突切除法的临床应用

目的研究慢性鼻窦炎患者实施鼻内镜下改良Swing-door技术钩突切除法的临床应用效果,为基层医院开展鼻内镜手术创造条件。方法对2012年11月至2013年6月我院收治的40例慢性鼻窦炎患者应用鼻内镜下改良Swing-door技术钩突切除法进行治疗。结果 40例患者共69侧鼻内镜手术,全部侧别的钩突均安全切除,即使鼻腔因二次手术缺乏解剖标志,上颌窦口也在较短时间一次开放成功,未发生1例眶内侧壁损伤,未发生1例鼻泪管损伤。结论改良Swing-door技术钩突切除法操作简单、并发症少,注重窦口区黏膜保护,损伤小,适宜在基层医院广泛推广。

Rate-Sensitive Numerical Analysis of Dynamic Responses of Arched Blast Doors Subjected to Blast Loading

Current practice in analysis and design of blast doors subjected to blast loading considers only simple boundary conditions and material properties. The boundary conditions and material properties, in fact, have considerable influence on the response of blast doors subjected to blast loading. In this paper, the dynamic responses of a reinforced concrete arched blast door under blast loading were analyzed by the finite element program ABAQUS, combined with a previously developed elasto-viscoplastic rate-sensitive material model. And the effect of the surrounding rock mass and contact effect of the doorframe were also taken into account in the simulation. It is demonstrated that the strain-rate effect has considerable influence on the response of reinforced concrete blast door subjected to blast loading and must be taken into account in the analysis.

Economic reform, open-door policy and changes in spatial development patterns in China

The study profiles and explains the significant changes that have taken place in China's spatial development patterns since the inception of its economic reform and opening two decades ago. Principal component analysis is used to delineate spatial patterns. The analyses show that prior to the reform China's spatial development pattern was characterized by the dominance of the three municipalities and the Northeast, as well as by both the coast-interior and the north-south disparities. Northern provinces were generally more industrialized and economically powerful than the southern ones. After two decades of reform, regional development has become multi-centered with South China, the Yangtze Delta and the Beijing-Tianjin area being the three most important regions of the country. The coastal provinces as a whole rose to prominence on China's economic map while the Northeast has diminished its clout. The coast-interior gap not only remains but may have widened. The north-south disparity also still exists but there has been a role reversal with the south now in the lead position. Virtually all inland provinces now find themselves at or near the low end of the development spectrum. We argue that the major reason for the recent shifts in Chinese space economy is the spatially differentiated economic growth resulted from the reform and open door policy and from the new, uneven development strategy adopted by the Chinese government. The paper discusses four specific factors that have reshaped China's spatial development patterns.

Multi-Criterion Optimal Design of Automotive Door Based on Metamodeling Technique and Genetic Algorithm

A method for optimizing automotive doors under multiple criteria involving the side impact, stiffness, natural frequency, and structure weight is presented. Metamodeling technique is employed to construct approximations to replace the high computational simulation models. The approximating functions for stiffness and natural frequency are constructed using Taylor series approximation. Three popular approximation techniques,i.e.polynomial response surface (PRS), stepwise regression (SR), and Kriging are studied on their accuracy in the construction of side impact functions. Uniform design is employed to sample the design space of the door impact analysis. The optimization problem is solved by a multi-objective genetic algorithm. It is found that SR technique is superior to PRS and Kriging techniques in terms of accuracy in this study. The numerical results demonstrate that the method successfully generates a well-spread Pareto optimal set. From this Pareto optimal set, decision makers can select the most suitable design according to the vehicle program and its application.

The mass and heat transfer process through the door seal of refrigeration

As one of the main reasons causing leakage heat load in a refrigerator,mass and heat transfer through refrigerator door seal is of great importance to be studied.In this paper,a model is presented for numerical simulation of mass and heat transfer process through refrigerator door seal,and an experiment apparatus is designed and set up as well for comparison.A two-dimensional model and tracer gas method are used in simulation and experiment,respectively.It can be found that the relative deviations of air infiltration rate between the simulated results and experimental results were less than 1%,and the temperature difference errors at two special points of the door seal were less than 2.03℃.In conclusion,the simulated results are in good agreement with the experimental results.This paper initially sets up a model that can accurately simulate the heat and mass transfer through the refrigerator door seal,and the model can be used in refrigerator door seal optimization research in the follow-up study.

Reliability Analysis of Metro Door System Based on FMECA

The metro door system is one of the high failure rate subsystems of metro trains. The Failure Mode, Effects and Criticality Analysis (FMECA) method is applied to analyze the reliability of metro door system in this paper. Firstly, failure components of the door are statistically analyzed, and the major failure components are determined. Secondly, failures are classified according to their impacts on operation, and methods of calculating failure mode criticality and the related coefficients are illustrated. Finally, the FMECA is detailed in the selected 12 failure modes, and the failure modes are discovered that they have the most significant effect on metro door system. The obtained results can be used for optimal design and maintenance of the metro door system.

Novel Door-opening Method for Six-legged Robots Based on Only Force Sensing

Current door-opening methods are mainly developed on tracked, wheeled and biped robots by applying multi-DOF manipulators and vision systems. However, door-opening methods for six-legged robots are seldom studied, especially using 0-DOF tools to operate and only force sensing to detect. A novel door-opening method for six-legged robots is developed and imple- mented to the six-parallel-legged robot. The kinematic model of the six-parallel-legged robot is established and the model of measuring the positional relationship between the robot and the door is proposed. The measurement model is completely based on only force sensing. The real- time trajectory planning method and the control strategy are designed. The trajectory planning method allows the maximum angle between the sagittal axis of the robot body and the normal line of the door plane to be 45°. A 0-DOF tool mounted to the robot body is applied to operate. By integrating with the body, the tool has 6 DOFs and enough workspace to operate. The loose grasp achieved by the tool helps release the inner force in the tool. Experiments are carried out to validate the method. The results show that the method is effective and robust in opening doors wider than 1 m. This paper proposes a novel door-opening method for six-legged robots, which notably uses a O-DOF tool and only force sensing to detect and open the door.

基于DOORS的嵌入式软件参数数据项设计方法

为了解决参数数据项在嵌入式软件开发过程中技术状态不显形、编码效率低、数据传递易出错等方面的问题,提出了一种基于DOORS的参数数据项设计方法。定义了参数数据项在高层需求和设计文档中的规格化表达形式;采用DOORS扩展语言脚本自动化提取参数数据项设计信息,采用C++等高级语言编程将参数数据项设计信息自动转换为PDI源码及相关文档。该方法可大大提高嵌入式软件参数数据项的开发效率及质量。