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。

常泰长江大桥主航道桥纵向约束索CFRP筋材及成品索试制试验研究

常泰长江大桥主航道桥为主跨1208 m的公铁两用双塔钢桁梁斜拉桥,采用温度自适应塔梁约束体系实现对温度的完全自适应,该体系采用CFRP索作为纵向约束索。CFRP索采用127-∅7 mm扭绞型热挤聚乙烯平行CFRP筋材成品索。为保证CFRP索的质量,首先在工业化生产线上进行CFRP筋材试制及静载拉伸试验,然后在CFRP筋材试制基础上,进行CFRP成品索的试制及静载拉伸试验研究。结果表明:CFRP筋材试拉伸的强度为3099~3886 MPa,拉伸弹性模量为181~201 GPa;CFRP成品索加载至大于100%公称破断索力时,索体内的CFRP筋材未出现开裂、损伤、断丝等现象,锚固体(锚具及铸体)未见异常,拉伸弹性模量大于160 GPa,试验结果均满足相关要求。

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。

行波效应对近断层高低塔斜拉桥地震响应的影响

以一座高低塔斜拉桥为研究对象,采用大质量法模拟非一致激励进行地震响应分析。研究不同纵向约束体系下考虑行波效应的脉冲型近断层高低塔斜拉桥的地震响应;探讨不同地震动类型与地震动传播方向下高低塔斜拉桥地震响应受行波效应的影响规律;分析不同脉冲周期地震动作用下斜拉桥地震响应随脉冲周期的变化规律。研究结果表明:相比于纵向阻尼体系与半漂浮体系斜拉桥,固结体系斜拉桥地震响应对视波速的变化更敏感;不同地震动输入方向下行波效应对斜拉桥地震响应影响规律有所不同;当视波速较小时,视波速对高塔和低塔内力差异影响较大;纵向阻尼体系斜拉桥地震响应随着脉冲周期的增大整体上呈先增大后减小的趋势。塔底内力随视波速的变化规律受脉冲周期的影响显著,当视波速较大,且脉冲周期与斜拉桥纵向一阶周期接近时,斜拉桥地震响应达到最大值。

Possible involvement of integrin signaling pathway in the process of recovery from restraint stress in rats

Objective To search novel genes or pathways involved in the recovery process after restraint stress in rats. Methods We compared the hypothalamus transcriptional profiles of two different recovery patterns （fast recovery vs slow recovery） from restraint stress in rats using oligonucleotide microarray, the recovery pattern was determined by the decrement of plasma adrenocorticotropic-hormone （ACTH） and corticosterone levels during one hour recovery period after stress. A real-time quantitative RT-PCR was applied to validate the differential expressed genes. Results Analysis of the microarray data showed that most of genes were not differentially expressed between fast recovery group and slow recovery group. Among the differentially expressed genes we found that talin, together with serine/threonine protein phosphatase PPl-beta catalytic subunit （PP-1B） and integrin α-6 precursor （VLA-6） genes, were at least 1.5 fold upregulated in the fast recovery group, while junctional adhesion molecule 1 （F11r） was 1.5 fold down-regulated in the fast recovery group. Conclusion The results implied that integrin signaling pathway may be involved in the recovery from restraint stress in rats. The present study provided a global overview of hypothalamus transcriptional profiles during the process of recovery from the restraint stress in rats. The integrin signaling pathway seems to be involved in the recovery process, which deserves further study to clarify the integrin-mediated recovery mechanism after restraint stress.

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。

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。

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。

机动车儿童座椅安全性研究综述

随着机动车安全技术的日益发展,儿童乘车安全的问题不断凸显,儿童乘车安全逐渐成为一项重要研究课题。车辆发生碰撞时,儿童座椅也称儿童约束系统(Child Restraint System,CRS)是影响儿童安全的决定性因素。针对乘用车儿童座椅安全性问题,综述了儿童安全座椅和儿童座椅安全性研究,以及机动车儿童座椅安全性功能和类型,并比较国内外对于座椅安全性相关技术法规和评价方法,阐述了儿童座椅安全性的研究现状。结合多名研究学者关于儿童座椅安全性的研究,列举多个不同影响因素对儿童座椅安全性的影响,有针对性地提出自适应匹配方法适用于不同儿童乘员使用集成式儿童约束系统的乘车安全和误使用等问题的相关优化建议,对于提高儿童座椅的安全性具有重要意义。

Dip2a regulates stress susceptibility in the basolateral amygdala

Dysregulation of neurotransmitter metabolism in the central nervous system contributes to mood disorders such as depression, anxiety, and post–traumatic stress disorder. Monoamines and amino acids are important types of neurotransmitters. Our previous results have shown that disco-interacting protein 2 homolog A(Dip2a) knockout mice exhibit brain development disorders and abnormal amino acid metabolism in serum. This suggests that DIP2A is involved in the metabolism of amino acid–associated neurotransmitters. Therefore, we performed targeted neurotransmitter metabolomics analysis and found that Dip2a deficiency caused abnormal metabolism of tryptophan and thyroxine in the basolateral amygdala and medial prefrontal cortex. In addition, acute restraint stress induced a decrease in 5-hydroxytryptamine in the basolateral amygdala. Additionally, Dip2a was abundantly expressed in excitatory neurons of the basolateral amygdala, and deletion of Dip2a in these neurons resulted in hopelessness-like behavior in the tail suspension test. Altogether, these findings demonstrate that DIP2A in the basolateral amygdala may be involved in the regulation of stress susceptibility. This provides critical evidence implicating a role of DIP2A in affective disorders.

Tree: Reducing the use of restrictive practices on psychiatric wards through virtual reality immersive technology training

BACKGROUND Restrictive practices(RPs)are defined by measures linked to physical and chemical restraints to reduce the movement or control behaviours during any emergency.Seclusion is an equal part of RPs intended to isolate and reduce the sensory stimulation to safeguard the patient and those within the vicinity.Using interventions by way of virtual reality(VR)could assist with reducing the need for RPs as it could help reduce anxiety or agitation by way of placing users into realistic and immersive environments.This could also aid staff to and change current RPs.AIM To assess the feasibility and effectiveness of using a VR platform to provide reduction in RP training.METHODS A randomised controlled feasibility study,accompanied by evaluations at 1 month and 6 months,was conducted within inpatient psychiatric wards at Southern Health National Health Service Foundation Trust,United Kingdom.Virti VR scenarios were used on VR headsets to provide training on reducing RPs in 3 inpatient psychiatric wards.Outcome measures included general self-efficacy scale,generalised anxiety disorder assessment 7(GAD-7),Burnout Assessment Tool 12,the Everyday Discrimination Scale,and the Compassionate Engagement and Action Scale.RESULTS Findings revealed statistically significant differences between the VR and treatment as usual groups,in the Everyday Discrimination Scale items Q8 and Q9:P=0.023 and P=0.040 respectively,indicating higher levels of perceived discrimination in the VR group.There were no significant differences between groups in terms of general self-efficacy,generalised anxiety disorder assessment 9,and Burnout Assessment Tool 12 scores.A significant difference was observed within the VR group for compassionate engagement from others(P=0.005)over time.Most respondents recorded System Usability Scale scores above 70,with an average score of 71.79.There was a significant reduction in rates of RPs in the VR group vs treatment as usual group with a fluctuating variability observed in the VR group likely due to external factors not captured in the study.CONCLUSION Ongoing advancement of VR technology enables the possibility of creating scenarios and simulations tailored to healthcare environments that empower staff by providing more comprehensive and effective training for handling situations.

高铁高墩大跨度连续刚构固结体系设计方案

为确定高铁高墩大跨度连续刚构合理的固结体系,以沈白高铁头道松花江特大桥主桥(75+136+136+75)m连续刚构为研究对象,采用MIDAS/Civil建立全桥空间有限元模型,研究分析单固结体系、两固结体系和三固结体系下结构内力、刚度、徐变、轨道平顺性、经济性。结果表明:主梁、主墩内力方面,三固结体系内力最大,单固结体系内力最小,两固结体系介于两者之间;刚度方面,三固结体系整体刚度最大,单固结体系整体刚度最小,两固结体系介于两者之间;徐变方面,满足徐变要求时结构所需梁高从小到大依次为单固结体系<两固结体系<三固结体系;轨道平顺性方面,采用中点弦测法、矢距差法检算时,三种体系均满足规范要求。采用竖曲线半径法检算时,结构所需梁高从小到大依次为单固结体系<两固结体系<三固结体系;经济性方面,两固结体系经济性优于单固结体系。

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。