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Based on some assumptions, the dynamic analysis model of anchorage system is established. The dynamic governing equation is expressed as finite difference format and programmed by using MATLAB language. Compared with theoretical method, the finite difference method has been verified to be feasible by a case study. It is found that under seismic loading, the dynamic response of anchorage system is synchronously fluctuated with the seismic vibration. The change of displacement amplitude of material points is slight, and comparatively speaking, the displacement amplitude of the outside point is a little larger than that of the inside point, which shows amplification effect of surface. While the axial force amplitude transforms considerably from the inside to the outside. It increases first and reaches the peak value in the intersection between the anchoring section and free section, then decreases slowly in the free section. When considering damping effect of anchorage system, the finite difference method can reflect the time attenuation characteristic better, and the calculating result would be safer and more reasonable than the dynamic steady-state theoretical method. What is more, the finite difference method can be applied to the dynamic response analysis of harmonic and seismic random vibration for all kinds of anchor, and hence has a broad application prospect. 相似文献
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基于等效Mohr-Coulomb屈服准则原理,通过岩体材料参数的人工换算,实现其在有限元软件Ansys中的应用,并论证了转化后的材料参数与原参数的大小关系,即转化后参数恒比原参数小。结合算例分析,得知采用等效Mohr-Coulomb屈服准则计算得到的岩质边坡安全系数偏小、保守,可用来模拟岩体材料;同时,对不同位移及应力工程精度要求的岩质边坡工程,提出采用不同屈服准则的建议。 相似文献
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921A钢是我国重要的舰船结构钢,研究921A钢在高温、高应变率条件下的动态力学性能对舰船结构防护设计和安全评估具有重要意义。采用电子万能试验机和带有同步组装系统的高温Hopkinson压杆试验装置,对921A钢在不同温度(25~500℃)、不同应变率(0.001~4000 s^(-1))下的准静态和动态力学性能进行了研究。结果表明,921A钢具有明显的应变率强化效应和热软化效应,应变率强化效应随温度升高逐渐减弱,热软化效应对应变率变化不敏感。考虑了应变、应变率和温度对力学性能的影响,拟合得到了921A钢的Johnson-Cook本构模型参数。开展了弹体高速撞击双层921A钢板的试验,并采用得到的Johnson-Cook本构模型参数进行了数值仿真,靶板弹孔平均直径和破坏形貌的仿真结果与试验结果吻合较好,验证了该模型能够较好地描述921A钢在高速冲击条件下的动态力学行为。 相似文献
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低速弹体贯穿钢筋混凝土多层靶的破坏特性 总被引:1,自引:1,他引:0
为获取大尺寸弹体对4层钢筋混凝土薄靶的贯穿破坏特性,开展了实验与仿真研究。以300 mm口径平衡炮作为发射平台,驱动280 kg截卵形弹体以337 m/s低速正贯穿4层抗压强度为41.8 MPa的钢筋混凝土薄靶,发现靶板破坏区域由锥形前坑区和后坑区组成。在此基础上建立了弹体正贯穿钢筋混凝土薄靶的破坏模型,并对破坏特性相关因素进行了分析。建立了有限元数值仿真模型,采用有限元分析软件LS-DYNA对整个贯穿过程进行了计算。将数值仿真结果与实验结果进行了对比,结果表明:速度及动能消耗最大误差分别为0.82%和6.21%,一致性较好;建立的数值仿真模型可用于弹体对多层靶侵彻能力的预估。 相似文献
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段建王伟许晓东 《机电产品开发与创新》2023,(6):65-68
在传统加工中,轴承套圈的上下料操作存在加工效率低、安全性差、生产成本高、上下料失误率大等问题,严重影响企业的生产效率。为解决这些痛点,团队结合多年实践经验,借助三维建模软件设计了一种轴承套圈自动化双夹具上下料输送线装置。具体针对该装置的导料装置、加工盘及夹具组件等主要组成部分进行了设计介绍,同时对该装置的工作过程进行了详细分析。实践证明,该装置在工作过程中,能够实现上料操作和下料操作同时执行,并精准完成上下料操作,无需增加额外的驱动设备,具有结构简单、成本低、效率高等优点。 相似文献
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Based on some assumptions, the dynamic governing equation of anchorage system is established. The calculation formula of natural frequency and the corresponding vibration mode are deduced. Besides, the feasibility of the theoretical method is verified by using a specific example combined with other methods. It is found that the low-order natural frequency corresponds to the first mode of vibration, and the high-order natural frequency corresponds to the second mode of vibration, while the third mode happens only when the physical and mechanical parameters of anchorage system meet certain conditions. With the increasing of the order of natural frequency, the influence on the dynamic mechanical response of anchorage system decreases gradually. Additionally, a calculating method, which can find the dangerous area of anchorage engineering in different construction sites and avoid the unreasonable design of anchor that may cause resonance, is proposed to meet the seismic precautionary requirements. This method is verified to be feasible and effective by being applied to an actual project. The study of basic dynamic features of anchorage system can provide a theoretical guidance for anchor seismic design and fast evaluation of anchor design scheme. 相似文献
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为了研究电解质离子尺寸对超级电容器电解液电化学性能的影响,自制了阳离子不同的2种电解质N,N-二甲基吡咯烷四氟硼酸盐(P_(11)-BF_4)和N-乙基-N-甲基吡咯烷四氟硼酸盐(P_(12)-BF_4),并分别配制成以碳酸丙烯酯(PC)为溶剂、浓度为1 mol/L的电解液;通过循环伏安、恒流充放电、交流阻抗谱研究了电解质离子尺寸对活性炭基超级电容器电化学性能的影响。结果表明:电解质离子尺寸和阳离子对称性共同影响着超级电容器的放电比电容,电解质离子尺寸越小,电解液的耐电压特性越好,超级电容器的工作电压越高;电解质离子尺寸的大小和阳离子的对称性共同影响着超级电容器的电化学性能。 相似文献