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1.
本文以预应力混凝土T型梁中梁模板的侧模板为例,介绍了30m大型钢模板的结构,加工所用设备,并详细介绍了中梁钢模板的加工工艺,提出了加工过程中应注意的几个技术问题并进行了经济效益分析,认为采用现场加工工艺是可行的. 相似文献
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本文在理论上建立了一套基于主动力反馈原理的新型主动阻尼悬架的设计和优化方法。首先提出了该主动阻尼悬架的实现模型,该模型是在传统的液力减振器的基础上,应用半主动控制的思想,结合力反馈的原理建立起来的内部液压反馈阻尼网络模型。理论优化分析和计算机仿真表明,通过该液阻网络模型,即可以实现电控的主动阻尼悬架的功能,它可以根据汽车行驶路况的好坏,自适应地调节悬架阻尼大小以实现主动阻尼悬架的最优控制。 相似文献
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The fatigue strength of a 300 mm2 stranded copper conductor was investigated experimentally and by finite element (FE) analysis. An analytical model was also developed and validated. Wires taken from the outer layer of the conductor were fatigue tested in tension–tension loading and compared with similar data for wires taken from a 95 mm2 conductor. The wire cross section was deformed due to the compacting process that was applied during fabrication. When corrected for stress concentrations due to the deformation the data for the two sets of wire fell within the same scatter-band. Full scale testing was carried out in a specially designed rig with constant tensile load and reversed displacement controlled bending with a fixed curvature variation. The loading is a simulation of the loading of a power cable hanging from a floating vessel through a bellmouth. Conductors were tested in two states; dry and lubricated. A finite element model was established for the copper conductor. The model was formulated by a combination of elastic beam and beam-contact elements that included the effects of friction. The effect of local bending due to contact forces was included in the model. Two contact conditions were investigated; the point (trellis) contact between adjacent layers of wire and the inline contact within each layer and between the first layer (centre wire) and the second layer. The FE model was validated by a calibration test of a full scale conductor, and by sensitivity studies varying the size and the number of elements of the model. Fatigue analysis of the conductor was carried out, based on the S–N curve for individual wires. Taking into account the effects of friction and local bending, agreement was obtained between predicted and experimental fatigue strength of the conductor, for the FE model as well as the analytical model. 相似文献
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随着海洋油气开发工程作业水深的增加,管中管结构承受的波浪、海流深海环境载荷增大,可能会引发强度破坏以及疲劳损伤,造成重大损失,所以开展深水条件下管中管系统的力学行为分析研究是有必要的。本文考虑了顶部张紧力和动态边界,利用有限元模型来模拟管中管结构及其力学行为。并利用接触单元模拟内外管接触的约束条件。综合统计了管柱的接触碰撞位置和应力危险位置,提出了新型扶正器的布置方案,以达到减缓碰撞保护管柱的目的,并对比了等距离设置扶正器的方案。通过对比研究发现本文提出的扶正方案有效减缓了内外管的应力等级,对于实际工程和研究具有一定指导价值。 相似文献
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提出宽横隔梁的设计思路,这种方法与斜横隔梁相比设计和施工都较为方便,受力较为明确。通过不同的模型建立方式分析了宽横隔梁桥的受力特点,给出了宽横隔梁桥设计应注意的几个问题,供桥梁设计参考。 相似文献
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Hydroelastic code-to-code comparison for a tension leg spar-type floating wind turbine 总被引:1,自引:0,他引:1
The development of robust design tools for offshore wind turbines requires knowledge of both wave and wind load models and response analysis. Verification of the numerical codes is required by the use of experiments and code-to-code comparisons. This paper presents a hydroelastic code-to-code comparison between the HAWC2 and USFOS/vpOne codes for a tension leg spar (TLS) wind turbine with a single tether. This concept is hence based on the TLP and Spar concepts. The comparison is performed using coupled hydroelastic time domain simulations. Several aspects of modelling, such as wave simulation, hydrodynamic and structural modelling, are addressed for the TLS. Wave-induced motions of the support structure affect the power performance of a wind turbine. Furthermore, overload of the tension leg should be avoided. In this paper, the motion and tension responses are compared. The tension leg introduces nonlinear effects on the spar motion. These nonlinear effects include combined-frequency effect such as double, difference and sum of wave, as well as natural pitch and surge frequencies. Hydrodynamic loads are based on a combination of the Morison formula and the pressure integration method. A comparison indicates that the motion and tension responses obtained in the two codes are in good agreement. 相似文献
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文中主要对重庆轻轨较新线李子坝车站采用高边坡挡墙群锚作用机理进行分析和研究,并通过对施工期和运行期现场实施监测,通过监测数据的统计分析和研究,从而验证该边坡的稳定性。 相似文献