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复杂河道工程测绘中往往受到植被茂盛、信号链接弱、山体遮挡等多种因素影响,导致传统测绘手段难以开展,通过在复杂河道工程测绘中对无人机LiDAR及倾斜摄影测量技术进行对比研究,找出两者之间的互补优势及融合方法。经试验证明,融合纹理影像信息的LiDAR数据既具有准确的空间地理信息,又具有清晰的地物边界信息。采用LiDAR数据校正的倾斜模型细节表达明显改善,模型轮廓表达清晰,人工判读更加容易。该成果有效克服了无人机单一测量技术及传统测量技术的弊端,可快速构建更加精准的河道数字孪生模型。 相似文献
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为增强桥梁结构的抗震能力和耐久性,针对大跨度铁路桥梁车致振动及地震响应的动力特点,以东平水道特大桥为工程背景,提出一种并联混合式减振方案,研究黏滞阻尼器对纵向滑移体系桥梁地震响应的控制效果,分析不同控制体系对列车荷载引起结构响应的影响。研究结果表明,黏滞阻尼器能显著减小大跨度铁路桥的地震结构位移和内力响应;泄压阀锁定装置对列车制动力和行车荷载的抑振能力优于黏滞阻尼器;当黏滞阻尼器和泄压阀锁定装置协同工作时,在降低二者出力值的同时可实现对列车荷载更好的控制效果,由于传力路径的改变,控制后的墩底剪力和弯矩均有所增大,但锁定装置的增大效应更小。 相似文献
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[Objectives]Electromagnetic pulse can seriously affect and even destroy naval shipborne electronic information systems, weapons, equipment and so on. Due to the complexity of the antenna port load circuit, it is necessary to formulate a numerical method which can easily obtain the antenna load current. [Methods]The induced current of the terminal is obtained on the basis of the finite-difference time-domain (FDTD) and Holland model. According to the Thévenin equivalent circuit, the conductor is equivalent to the voltage source to realize decoupling between the conductor and load end, and the load circuit is solved using Simulink software.[Results]Compared with the traditional terminal model, this method is simple and feasible for high-order circuit processing. The effectiveness of the model is verified using non-linear elements and parallel capacitors and resistors as the load respectively. The results show that the calculation results of this method are consistent with those of the traditional methods. Finally, the antenna of the end-connected protect- or is calculated. The results show that the lead inductance caused by the installation of the protector is an important factor affecting the protection performance.[Conclusions]The method proposed in this paper can greatly reduce the simulation complexity of the coupling current of an antenna with a complex load, giving it useful reference value for the field of ship electromagnetic pulse protection design. © 2023 Editorial Department of Chinese Journal of Ship Research. All Rights Reserved. 相似文献