共查询到19条相似文献,搜索用时 203 毫秒
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适坠性已经并将继续是飞机安全的一个重要关注点。为了研究不同滚转角度对机身结构动态响应特性的影响,针对典型的运输类飞机机身结构,建立货舱地板下部为波纹板布局形式的机身段有限元模型,分析该机身段在0°、5°、10°和15°的滚转角度下,以6.67 m/s的坠撞速度撞击刚性地面时的坠撞特性,对比分析不同滚转角度下机身段的破坏模式和座椅与地板连接处的加速度—时间历程曲线。结果表明:不同滚转角度会对机身结构的变形以及座椅处加速度响应产生显著影响,采用合适的应急着陆方式可以有效提高飞机的适坠性能。 相似文献
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建立了含货舱门的大型民机机身框段结构适坠性分析的全尺寸非线性有限元模型,模型中考虑了机身框、长桁、蒙皮、货舱及行李、客舱地板、客舱吊柜和座椅。利用该模型对机身框段进行了垂直坠撞仿真分析,坠撞速度为9.14 m/s,采用动力学软件MSC.Dytran进行求解,计算得到机身框段结构的变形和试验中各测量点处的加速度响应。计算结果与试验结果的吻合验证了所建模型的有效性。在该模型的基础上,对机身框段在不同滚转角垂直坠撞工况下的适坠性进行了分析。结果表明:在所计算的工况中,当飞机左滚12°和右滚8°坠撞时,机身结构破坏最严重,乘员承受的过载最大。货舱门结构增加了舱门侧的机身结构刚度,使机身结构左右变形不对称,含舱门侧的机身变形较小,含舱门侧的乘员承受过载较大。 相似文献
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保护乘员的生命安全是飞机适坠性设计的最终目标。为了更为准确的模拟乘员在坠撞过程中的动响应及伤害情况,利用LS-Dyna构建了包含假人及座椅约束系统的机身段坠撞仿真模型,对机身段在垂向撞击速度为9. 14 m/s时结构及乘员的动响应进行了详细分析,包括机身结构的吸能特性及破坏模式、舱内设施的系留状况、乘员的运动及伤害情况等,并通过与试验数据的对比验证了坠撞仿真模型的可信性;最后,开展了民机适坠性评估方法研究,通过对相关适航条款、咨询通告及标准的解读和梳理,提出了以生存空间、系留强度、乘员伤害、撤离通道和坠撞后环境为考核指标的民机适坠性综合评估方法。机身段适坠性分析表明,垂直坠撞环境下乘员的伤害模式主要为腰椎和小腿伤害,坠撞过程中乘员腰椎最大压缩载荷为6. 78 kN,小腿胫骨最大轴向压缩载荷为7. 46 kN;利用提出的适坠性综合评估方法对所构建民机的适坠性进行了系统评估,可知其适坠性较好,除乘员腰椎载荷稍微超出适航规定值而需要进行相应的设计改进之外,其余评估指标皆符合要求。 相似文献
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针对某型飞机FS380到FS500确定机身段,研究了不同冲击条件对机身结构动态响应特性的影响。建立了机身试验段的等比简化有限元模型。分析了0滚转角、带有10°左滚转角以及带有纵向加速度的情况下,垂直坠撞速度v=9.133 m/s时的冲击特性。对比分析了各种情况下机身框段的变形情况和座椅位置处的加速度-时间历程曲线。结果表明:冲击条件的改变会对机身结构的变形以及座椅处加速度的变化产生影响:左滚转角的出现会改变机身的变形量以及峰值加速度的出现时间,纵向冲击的加入会增加地板的变形量但会有限地减小座椅处的峰值加速度,采用合适的应急着陆方式能提高飞机的耐坠毁性能。 相似文献
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基于有限元法和Taguchi方法的移动硬盘耐撞性能稳健设计 总被引:1,自引:0,他引:1
运用Taguchi参数设计方法,提出了基于数值模拟的移动硬盘跌落冲击耐撞性能稳健设计方法。以6.3cm(2.5in)移动硬盘为研究对象,建立了基于有限元软件ANSYS/LS-DYNA的移动硬盘跌落冲击三维有限元模型。分析了关键结构参数对移动硬盘耐撞性能稳健性的影响,进行了移动硬盘耐撞性能稳健设计,获得使磁盘盘片接触面等效应力对地面硬度变化具有稳健性的最优参数水平组合,并进行了仿真试验验证分析。该方法为改进设计提高移动硬盘耐撞性能提供了理论依据。 相似文献
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Hee-Young Ko Kwang-Bok Shin Kwang-Woo Jeon Seo-Hyun Cho 《Journal of Mechanical Science and Technology》2009,23(10):2686-2693
This paper describes the results of the numerical evaluation on crashworthiness and rollover characteristics of a lowfloor
bus vehicle made of sandwich composites. The sandwich composite used for the vehicle structures was composed of aluminum honeycomb
core and WR580/NF4000 glass-fabric/epoxy laminate facesheets. Material tests were conducted to determine the input parameters
of the composite laminate facesheet model and the effective equivalent damage model for the orthotropic honeycomb core material.
Crashworthiness and rollover analysis of the low-floor bus was conducted using the explicit finite element method (FEM) analysis
code LS-DYNA3D with the lapse of time. The crash condition of the low-floor bus was a frontal accident with a speed of 60
km/h. Rollover analysis was done according to the safety rules of the European standards (ECE-R66). The angular and translation
velocity and its angle with the ground just before impact for rollover were calculated using the dynamic analysis program.
The results showed that the survival spaces for the driver and passengers were secured against frontal crashworthiness and
rollover of the low-floor bus. In addition, the modified Chang-Chang failure criterion is recommended to predict the failure
modes of the composite structures for crashworthiness and rollover analysis. 相似文献
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Crashworthiness study of a keel beam structure 总被引:1,自引:0,他引:1
In this paper, crashworthiness of the energy-absorbing keel beam that could be used for sub-floor of an aircraft was numerically studied using finite element software (ABAQUS/EXPLICIT). Effects of various parameters, i.e. web thickness, radius of everting stringer, and friction coefficient, were investigated and the conditions under which the keel beam could produce progressively crushing deformation were explored. The results show that web thickness, t, and radius of everting stringer, r, have great influence on the performance of the keel beam. When the ratio of r/t is in the range of 4-6, a low peak force (peak force reduction of 50%), stable and relative high stress plateau, and progressively crushing deformation mode can be produced from the energy-absorbing keel beam. By selecting appropriates parameters, energy absorption behavior has been significantly improved comparing with the traditional keel beam. Finally, a new energy-absorbing keel beam with variable web thickness was proposed. It has been demonstrated that the keel beam with variable web thickness is an ideal crashworthiness structure. It could not only significantly reduce the peak force, but also remain the stable and effective force plateau; meanwhile avoid web buckling. 相似文献
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以平行四杆柔性移动副为研究对象,基于伪刚体模型,采用虚功原理对机构的整体刚度进行了分析。在此基础上,将加工误差、作用载荷、杆长尺寸、弹性模量等参数均视为随机变量,建立了柔性移动副输出运动精度的可靠性分析模型,通过算例分析了柔性移动副中各项随机参数的变化对运动精度可靠度的影响。 相似文献
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以通航某轻型飞机CATIA三维模型为基础,采用动力学分析理论对其进行了动力学有限元仿真研究,建立了机翼、机身、平尾、垂尾、模型各部分连接等结构的动力学分析模型。文中对飞机结构进行了设计特点和受、传力分析,制订了动力学分析模型的简化原则,对用到的特殊单元进行了简单的介绍。 相似文献
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One of the most significant problems in the processing of composite material is residual stress. The high residual stress
may cause cracking in the matrix without external loads and degrade tile integrity of composite structures. In this Study,
thermo-viscoelastic residual stresses occurred in an aluminum liner-inserted composite cylinder are investigated. This type
of the structure is used for rocket fuselage due to the convenience to attach payloads and equipment to the metal liner by
machining. The time and degree of cure dependent thermo-viscoelastic constitutive equations are developed and coupled with
a thermo-chemical process model. Thee equations are solved with the finite element method to predict the residual stresses
in the composite cylinder and also in the interface between the liner and file composite dining cure. 相似文献