Design and Optimization for the Occupant Restraint System of Vehicle Based on a Single Freedom Model

Throughout the vehicle crash event, the interactions between vehicle, occupant, restraint system (VOR) are complicated and highly non-linear. CAE and physical tests are the most widely used in vehicle passive safety development, but they can only be done with the detailed 3D model or physical samples. Often some design errors and imperfections are difficult to correct at that time, and a large amount of time will be needed. A restraint system concept design approach which based on single-degree-of-freedom occupant-vehicle model (SDOF) is proposed in this paper. The interactions between the restraint system parameters and the occupant responses in a crash are studied from the view of mechanics and energy. The discrete input and the iterative algorithm method are applied to the SDOF model to get the occupant responses quickly for arbitrary excitations (impact pulse) by MATLAB. By studying the relationships between the ridedown efficiency, the restraint stiffness, and the occupant response, the design principle of the restraint stiffness aiming to reduce occupant injury level during conceptual design is represented. Higher ridedown efficiency means more occupant energy absorbed by the vehicle, but the research result shows that higher ridedown efficiency does not mean lower occupant injury level. A proper restraint system design principle depends on two aspects. On one hand,the restraint system should lead to as high ridedown efficiency as possible, and at the same time, the restraint system should maximize use of the survival space to reduce the occupant deceleration level. As an example, an optimization of a passenger vehicle restraint system is designed by the concept design method above, and the final results are validated by MADYMO, which is the most widely used software in restraint system design, and the sled test. Consequently, a guideline and method for the occupant restraint system concept design is established in this paper.

Occupant Restraint System Simulation and Optimization Based on TESW

Integrated into the development process of a chinese independent brand class sedan,optimization about occupant restraint system associated with dummy chest deceleration is studied.Based on this simulated vehicle deceleration and the target vehicle′s chest deceleration,tipped equivalent square wave(TESW)is calculated by combining the average stiffness kof occupant restraint system and the average free flight time t*from the existant CNCAP(China new car assessment program)tested cars.After proposing modeling regulations of occupant restraint system and establishing mathematical dynamic modelling(MADYMO)for occupant restraint system of the target vehicle,four optimization design parameters namely vent area A,load limit L,seat belt extension ratio Band pretension force Fare selected by weighted injury criteria(WIC)rule and the first-order response surface method.The four parameters have been optimized by using orthogonal test design of four factors with five levels and the optimum combination A5L1B1F5 has been chosen by range and variance analyses.The results show that occupant restraint system performance has been optimized and improved,while meeting the chest deceleration calculation peak based on TESW.

Multi-Parameter and Multi-Objective Optimization of Occupant Restraint System in Frontal Collision

To solve the constraints of multi-objective optimization of the driver system and high nonlinear problems, according to the relevant dimensions of a car, we build a simulation model with Hybrid Ⅲ 50th dummy driver constraint system. The comparison of the driver mechanics index of the experimental data with the simulation data in the frontal crash shows that the accuracy of simulation model meets the requirements. The optimal Latin test design is adopted, and the global sensitivity analysis of the design parameters is carried out based on the Kriging model. The four most sensitive parameters are selected, and the parameters are solved by a multi-island genetic algorithm.And then the nonlinear programming quadratic line(NLPQL) algorithm is used to search for accurate optimization. The optimal parameters of the occupant restraint system are determined: the limiting force value of force limiter 2 985.603 N, belt extension 12.684%, airbag point explosion time 27.585 ms, and airbag vent diameter 27.338 mm, with the weighted injury criterion(WIC) decreased by 12.97%, the head injury decreased by 22.60%, and the chest compression decreased by 7.29%. The results show that the system integration of passive safety devices such as seat belts and airbags can effectively protect the driver.

Influence Analysis and Vibration Restraint Solutions Research on the Underwater Acoustic Monitoring System

In order to reduce the hydrodynamic and structural influences on the detection accuracy especially in the very-lowfrequency range, some vibration restraint methods are raised, which are the wrapped fairing improvement, the floating body shape improvement and the cable vibration reduction treatment. Through the improvement analysis and experimental comparison, the final treatments are proposed, namely the multilayer wrapped fairing structure with composite materials, the floating body with NACA0024 airfoil section and X-shape tail spoiler, as well as the brush cable. The sea test is carried out to evaluate the vibration restraint effect. Through comparison of the responses to the ocean ambient noise and the direction of arrival(DOA) estimations with the same underwater transmitting transducer, the results indicate that the horizontal floating platform with vibration restraint treatment has obvious flow resisting effect especially in low frequency range and more accurate DOA estimation.

DEVELOPMENT OF NEW GENERATION THERMOMECHANICAL SIMULATOR-MULTI-AXIS RESTRAINT COMPRESSION(MARC-STRAIN^(TM))SYSTEM

Ultrafine grain size is often achieved by severe plastic deformation. A few techniques have been devel- oped to achieve severe plastic deformation,such as equal channel angular (ECA ) processing, torsion, and accumulative roll bonding (ARB) techmpues. This paper will introduce a moftiaxis deformation technique which can achieve essentially unlimited strain with constant deformation volume. The mul- tiaxis deformation can be fully restrained or unrestrained.The bulk volume of a multiaxis restraint compression specimen can be easily machined into mechanical testing specimens for mechanical property measurement and other studies.

Analytical solutions for the restraint effect of isolation piles against tunneling-induced vertical ground displacements

This paper presents a simplified elastic continuum method for calculating the restraint effect of isolation piles on tunneling-induced vertical ground displacement,which can consider not only the relative sliding of the pile‒soil interface but also the pile rowesoil interaction.The proposed method is verified by comparisons with existing theoretical methods,including the boundary element method and the elastic foundation method.The results reveal the restraining mechanism of the isolation piles on vertical ground displacements due to tunneling,i.e.the positive and negative restraint effects exerted by the isolation piles jointly drive the ground vertical displacement along the depth direction from the original tunneling-induced nonlinear variation situation to a relatively uniform situation.The results also indicate that the stiffness of the pile‒soil interface,including the pile shaft‒surrounding soil interface and pile tip-supporting soil interface,describes the strength of the pile‒soil interaction.The pile rows can confine the vertical ground displacement caused by the tunnel excavation to the inner side of the isolation piles and effectively prevent the vertical ground displacement from expanding further toward the outer side of the isolation piles.

Research on Innovation of Fair Competition Review System in Shenzhen

The Shenzhen Fair Competition Review System has experienced internal review and cross-examination since its inception.However,it is still dominated by the self-review of policy-making organs,with a lack of effective control and restraint mechanisms.In addition,insufficient compensatory effect of the external review has led to weak effectiveness of social supervision.Shenzhen is currently the pilot of an independent fair competition review system.The Fair Competition Commission can be set up as an independent review body.Then,the operational mechanism should be improved and the constraints and incentives should be set up scientifically.Last but not the least,by strengthening the social supervision network for fair competition review,the legality and rationality of a wide range of local regulations,rules,and normative documents will be reviewed,thereby regulating the behavior of policy-making organs.

ICU患者身体约束决策支持系统的研发与应用

目的:研发ICU患者身体约束决策支持系统并评价其临床应用效果,为护士进行患者身体约束决策提供便利。方法:成立研发小组,构建ICU患者身体约束影响因素预测模型并进行验证,以此为基础开发ICU患者身体约束决策支持系统并投入使用。选取2022年8月至2023年3月江苏省某三级甲等医院ICU的764例患者为研究对象,将患者随机分为干预组(n=366)和对照组(n=398),对照组护士实施基于经验性评估的常规身体约束流程,干预组护士实施基于ICU患者身体约束决策支持系统的身体约束流程,比较两组患者的身体约束率、谵妄发生率、非计划性拔管发生率;同时验证ICU患者身体约束决策支持系统与约束决策轮的一致性。结果:使用ICU患者身体约束决策支持系统后,干预组患者的约束率为24.9%,谵妄发生率为2.2%,均低于对照组(P<0.05);两组非计划性拔管发生率差异无统计学意义(P>0.05)。ICU患者身体约束决策支持系统与约束决策轮Kappa一致性检验结果为0.853(P<0.001),显示结果一致性较好。结论:ICU患者身体约束决策支持系统可以应用于临床并辅助护士决策,在有效降低身体约束率及谵妄发生率的同时不会增加非计划性拔管发生率。

侧面柱碰撞工况下驾驶员侧气囊优化设计

为提高侧面柱碰撞工况下驾驶员侧气囊安全得分,依据2021版C-NCAP管理规则搭建汽车侧面柱碰撞乘员约束系统模型,实车碰撞及仿真结果表明,头部、腹部、骨盆安全得分均达标,胸部伤害较严重,得分较低。通过优化侧气囊的袋型和气孔直径,提升胸部肋骨安全得分。优化后结果表明,胸部上肋骨、中肋骨、下肋骨压缩量分别减小30.97%、8.26%、13.71%,验证了优化方案的有效性。

大跨度双联连续钢管混凝土拱桥结构体系设计研究

为研究大跨度双联连续钢管混凝土拱桥的合理结构体系及中央拱座合理刚度,以主跨2×405 m渝湘复线双堡特大桥为背景,采用MIDAS Civil软件建立全桥有限元模型,分析考虑自重、汽车荷载和基础沉降作用下,拱桥刚接、铰接、半刚性连接约束体系和不同中央拱座刚度对桥梁力学性能的影响。结果表明:自重、汽车荷载和基础沉降作用下各结构体系力学性能均满足规范要求。双刚接方案拱肋变形对称,结构受力良好,且构造简单、施工方便。中央拱座刚度从0.8 EI(EI为原设计方案中央拱座截面刚度)增加至2.0 EI,自重产生的最大变形基本不变,最大拉应力减小了0.33%,最大压应力减小了0.47%,结构力学性能改善效果不明显。双堡特大桥结构体系推荐采用双刚性连接,中央拱座合理刚度取值为0.8 EI,全桥有限元计算结果表明,该结构体系的强度、刚度、稳定性均满足规范要求。

建筑结构隔震技术研究进展

建筑结构隔震技术通过在建筑结构底部或中间楼层设置隔震装置,延长结构的自振周期,并提供适当的阻尼使得结构的响应大幅度减小,能够更有效地保护房屋结构以及室内设备的安全,可显著提升建筑震后功能可恢复能力。目前建筑结构隔震技术已经有较为成熟的技术产品和工程应用,已广泛应用于住宅、医院、学校、博物馆和图书馆等建筑中。随着《建设工程抗震管理条例》的颁布,预期隔震技术将有更广阔的应用场景。隔震建筑也将逐步从低层、简单建筑结构向高层、复杂建筑结构的方向发展。目前常用的隔震装置存在着抗拉能力不足、对竖向地震或竖向环境振动减振效果不足、控制频宽窄、适应性不足以及使用状态及损伤状态难以监测等问题。为此,众多学者针对以上问题进行了深入研究,开发了抗拉隔震支座、三维隔震(振)支座、半主动隔震支座和隔震支座的健康监测系统,为扩展隔震技术的应用范围提供了解决方法。目前,相关研究偏重于新型隔震装置的性能研究,未来应全面考虑新型隔震装置对于建筑的影响,提出配套的设计方法,并进行示范性工程应用,加快隔震技术的推广。

汽车正面碰撞后排小体位假人伤害研究及优化

提出了一种相应的伤害优化方案,基于C-NACP正面碰撞工况搭建碰撞分析模型,同时通过与正面100%重叠刚性壁障碰撞试验的HybridⅡ5th女性假人试验数据进行对比来验证模型的可靠性。基于对标结果进行优化设计,对比分析不同优化方案对乘员安全性的影响趋势。确定优化方案,即增加碰撞锁止锁舌、线性预紧器配置,增加座椅刚度,调整安全带限力值。与原始方案相比,在碰撞过程中后排女性假人总体得分提升84%。根据C-NCAP星级评定规程,此后排女性假人得分高于94%,成绩优秀,验证了方案的有效性,可为后排小体位假人伤害的优化研究提供参考。

铁路高低塔混合梁斜拉桥约束体系设计

汉巴南铁路嘉陵江大桥主桥采用(45+55+58+335+58+49)m高低塔混合梁斜拉桥,以降低结构内力和位移响应、优化行车条件及轨道结构使用性能为目标,对大桥的约束体系进行设计。选取3种纵向约束、5种横向约束体系方案,建立有限元模型分析各方案静力及地震作用下的结构响应,得到纵向采用阻尼约束或支座位移约束的半飘浮体系时结构静力响应差异较小,采用阻尼约束时的地震响应较小,横向采用阻尼约束或挡块限位约束均能实现较好的耗能限位效果,采用阻尼约束时的减震效率不高。根据各方案地震响应结果,结合行车条件及轨道结构的性能需求,该桥纵向采用组合式约束体系,运营及设计地震作用下为带支座纵向位移约束的半飘浮体系,罕遇地震作用下为带纵向阻尼约束的半飘浮体系;横向采用固定支座+限位挡块的方案;根据约束方案确定了约束布置和相关技术参数,实现了铁路桥梁的性能目标。

中国古代息讼制度的三重维度及其现代启示

息讼制度是中国古代社会制度的重要文化遗产,在维护社会和谐中发挥着独特作用。考察中国古代息讼制度,儒家的礼之用、和为贵,道家的无为而治,法家的定纷止争是其理论来源;先秦时期的式微与萌芽、秦汉时期的形成与确立、魏晋南北朝至隋唐时期的成熟与发展、宋元明清时期的完备与繁荣是其历史嬗变图景;防范争讼、依礼息讼、调解止讼是其实践运行方式;践行“以和为贵”的理念,把基本道德规范转化为法律规范,完善中国特色多元纠纷解决机制是其蕴含的现代启示。

我国社区戒毒协议存在的问题及完善建议

社区戒毒制度建立在行政处理轻缓化和社会化理念的基础上,从戒毒者“病人”的角色出发,通过行政机关与社区戒毒者签订社区戒毒协议,并在社会多元化主体的参与下实现对戒毒者的矫正和教育。社区戒毒协议是社区戒毒制度执行的重要载体。然而社区戒毒协议在实践中却因行政权的泛化,致使社区戒毒制度逐步沦为机构化处遇的前置或替代手段。究其原因,一方面是社区戒毒协议自身存在不足,另一方面是缺乏对行政权的监督和制约。因此,应完善社区戒毒协议的具体内容,明确社区戒毒协议的法律属性,建立起以社区戒毒协议为“桥梁”的司法权对行政权的监督制约机制,从而促进社会化处遇的社区戒毒制度的发展和完善。

开放式创新平台激励与约束机制对用户创新行为的影响

平台的开放共享特征促使用户更主动地参与到价值创造活动中,企业吸纳用户参与创新过程成为其提升创新能力的重要途径。从认知—情感双重视角出发,以创新自我效能感、情感承诺为中介变量,以主动型人格为调节变量,探究开放式创新平台激励与约束机制对用户创新行为的影响机制及边界条件。结果显示,开放式创新平台激励机制、约束机制对用户创新行为均具有正向影响;创新自我效能感与情感承诺分别在开放式创新平台激励机制、约束机制与用户创新行为间发挥部分中介作用;主动型人格分别在开放式创新平台激励机制、约束机制与用户创新行为间发挥正向调节作用。

汽车乘员约束系统仿真及其参数优化

在汽车有限元模型基础上建立了乘员约束系统模型,进行了100%正面刚性壁碰撞仿真分析。结合碰撞分析中假人伤害值,采用灵敏度分析筛选出对约束系统影响较大的参数作为设计变量,构建了关于加权伤害指标的Kriging代理模型,运用多岛遗传算法进行参数优化。结果表明,加权伤害指标降低了38.92%,达到设计目标。

Physical restraint in mental health nursing: A concept analysis

Objective: Physical restraint is frequently used in medical services,such as in mental health settings,intensive care units and nursing homes,but its nature varies in different institutions.By reviewing related literature,this study aims to clarify the concept of physical restraint in mental health nursing.Method: Three databases (PubMed,PsyclNFO and CINAHL) were retrieved,and Walker and Avant's concept analysis method was used to analyze the concept of physical restraint in mental health nursing.Results: Physical restraint is a coercive approach that enables the administration of necessary treatment by safely reducing the patient's physical movement.It should be the last option used by qualified personnel.Antecedents of physical restraint are improper behavior (violence and disturbance) of patients,medical assessment prior to implementation and legislation governing clinical usage.Consequences of physical restraint are alleviation of conflict,physical injury,mental trauma and invisible impact on the institution.Discussion: This study defined the characteristics of physical restraint in mental health nursing.The proposed concept analysis provided theoretical foundation for future studies.

Physical restraints:An ethical dilemma in mental health services in China

Given that physical restraints cause adverse effects to patients and nurses,their wide and frequent use has resulted in various clinical and ethical controversies in mental health services.The rate of physical restraints is significantly higher in China than in other countries.Some western and domestic media blamed relevant institutions for compromising the basic rights of psychiatric patients.Therefore,this study aims to collect and synthesize the relevant ethical evidence and to provide corresponding guidance for the nursing practice based on the current situation of the mainland of China.This study synthesized the ethical issue according to the ethical principle of autonomy,justice,beneficence,and nonmaleficence.Given the current situation where the nursing workforce is limited and the mental health service is under-developed in China,applying physical restraints in the psychiatric inpatients to guarantee the safety of patients and nurses is crucial.In regard to respect the basic rights of psychiatric patients,it is recommended to protect the their autonomy,and eliminate the adverse effects of physical restraint.This goal would be achieved by ensuring the informed consent,providing humane care,and regulating the implementation of physical restraints.

Vibration Characteristics and Power Transmission of Coupled Rectangular Plates with Elastic Coupling Edge and Boundary Restraints

Coupled-plate structures are widely used in the practical engineering such as aeronautical,civil and naval engineering etc.Limited works can be found on the vibration of the coupled-plate structure due to the increased mathematical complexity compared with the single plate structure.In order to study analytically the vibration characteristics and power transmission of the coupled-plate structure,an analytical model consisting of three coupled plates elastically restrained along boundary edges and elastically coupled with arbitrary angle is considered,in which four groups of springs are distributed consistently along each edge of the model to simulate the transverse shearing forces,bending moments,in-plane longitudinal forces and in-plane shearing forces separately.With elastic coupling condition and general boundary condition of both flexural and in-plane vibrations taken into account by setting the stiffness of corresponding springs,the double Fourier series solution to the dynamic response of the structure was obtained by employing the Rayleigh-Ritz method.In order to validate the model,the natural frequency and velocity response of the model are firstly checked against results published in literatures and the ANSYS data,and good agreement was observed.Then,numerical simulation of the effects of several relevant parameters on the vibration characteristics and power transmission of the coupled structure were performed,including boundary conditions,coupling conditions,coupling angle,and location of the external forces.Vibration and energy transmission behaviors were analyzed numerically.The results show that the power transmission can be significantly influenced by the boundary restraints and the location of excitation.When the excitation is located at the central symmetry point of the model,the energy flow shows a symmetrical distribution.Once the location deviates from the central symmetry point,the power circumfluence occurs and the vortex energy field is formed at high frequency.