共查询到19条相似文献,搜索用时 468 毫秒
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由于传统方法对船舶螺旋桨的加工刀位规划精度不高的现象,提出舰船螺旋桨四轴曲面数控加工刀位模拟规划分析。根据螺旋桨四轴曲面的结构特点,确定螺旋桨的轴向基准,对刀位进行模拟计算,生成数控加工刀位轨迹,以HOOPS为平台,对螺旋桨数控加工进行模拟,实现螺旋桨四轴曲面刀位规划。仿真实验结果表明,数控加工规划法比传统规划方法的螺旋桨加工精度高16.3%,具备有效性。 相似文献
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普通制造工艺不能加工出表面粗糙度、间隙倾角都符合应用要求的船用鼓形齿联轴器机械。为解决上述问题,对普通大型船用鼓形齿联轴器机械加工工艺进行改进设计。通过齿面最小间隙分布情况研究、最大轴间倾角确定2个步骤,完成船用鼓形齿联轴器机械结构特点分析。在此基础上,通过最佳切削参数确定、机械齿联轴加工曲面确定、粗糙机械磨平流程完善3个步骤,完成改进后加工工艺的顺利应用。设计对比实验结果表明,应用改进后普通大型船用鼓形齿联轴器机械加工工艺,能同时降低机械表面粗糙度与机械间隙倾角。 相似文献
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在此介绍的是一种用于船舶轴系法兰螺栓孔加工的专用机械(如图)。本机特点:系采用了双头蜗杆、蜗轮为传动结构;主轴以滚动轴承和双向推力球轴承为支承结构;采取燕尾导轨形式;由丝杠螺母和进给手轮组成进给机构,从而使得该机主轴能承受双轴向作用力,进给运动平稳,在使用时还可以旋动调整螺钉24实现对 相似文献
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为了提高水下机器人设计和制造的机械强度,提出一种基于连续体模型应力评估的水下机器人刚度强化设计方法。构造水下机器人刚度强化评估的应力学结构模型,分析机器人刚度强化加工的控制约束参量,采用连续体模型应力评估方法进行水下机器人的刚度加工机械设计的荷载力学分析,实现机器人解耦构型的机构耦合度、运动灵巧度、方位特征、构件应力以及屈服强度等参量的解耦运算,得到机器人机械结构优化构型的位置正解,通过应力评估和结构解耦性设计,提高水下机器人的水下抗载荷能力和强度。仿真结果表明,采用该方法进行水下机器人刚度强化设计,机器人的机械弹性载荷较高,水下应力载荷和抗压能力得到提升,对机器人机械设计的构型优选和加工工艺改进具有较好指导价值。 相似文献
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气浮结构的运动特性研究 总被引:2,自引:1,他引:1
文章通过理论分析和试验研究探讨了气浮结构的运动特性。按单自由度刚体弹簧体系建立了气浮结构的升沉和摇摆运动方程,进而求气浮结构运动的固有周期,并对气浮结构的运动特性进行了讨论分析。文中引进的气浮力折减系数ka体现了气浮体的恢复力刚度系数与普通浮体的差异,该参数对气浮体的浮态、稳性、运动特性都有很大的影响。理论分析和试验表明气体浮体的固有周期比相应实浮体的大。结合理论和试验,确定了气浮结构作升沉运动时附连水质量系数的取值。摇摆运动的附连水质量系数的确定较为复杂,还需作进一步的研究。 相似文献
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现代舰船的直升机起降时会通过轮胎将载荷作用于飞行甲板的板架上,这种载荷通常被称为轮印载荷。除此之外,相对于传统加筋板结构形式,I型夹层结构具有轻质、高比强度等优点,是一种可以应用于船舶飞行甲板的新型结构形式。本文针对轮印载荷局部重载和位置不确定的特点,设计了合理的试验贴片方案及加载程序,并将试验数据与理论值对比,分析误差原因,研究I型夹层板架结构的板格在四种典型位置轮印载荷作用下的静强度力学性能。试验结果表明,夹层板架结构在载荷附近测点的应力水平较大,同时其上面板沿船宽方向的弯曲应力大于沿船长方向的弯曲应力,而下面板2个方向的弯曲应力特性与上面板相反。这些结论对于I型夹层板架结构在轮印载荷下的力学性能研究具有重要意义。 相似文献
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This paper presents a fluid-structure-material coupling analysis for the interaction between water waves and a very large floating laminated structure (VLFLS), which is consisted of two enhanced ultrahigh-performance concrete (UHPC) panels and a middle lightweight foamed rubber core. The representative volume element (RVE) method is used to design the mechanical properties of enhanced UHPC and foamed rubber, and the parameterized formulas are presented to reveal the dependency between macroscale mechanical properties and mesoscale hierarchical characteristics. By idealizing the rubber core as a uniformly distributed spring layer, an eighth-order differential equation of motion of the laminated structure is derived. In the context of linear potential flow theory, a hydroelastic analytical model is developed for the floating laminated structure with finite length under wave action. In the process of solving velocity potentials, a complicated dispersion equation for the wave motion below the laminated structure is derived, and this equation contains two pairs of conjugate complex roots with positive real parts. The various hydrodynamic quantities, including reflection coefficient, transmission coefficient, deflection, shear force, and bending moment, are calculated. The hydroelastic model is confirmed by considering the convergence of calculation results and the energy conservation of wave propagation. The coupled effects of wave action, material characteristics, structural parameters, and edge conditions on the hydroelastic and mechanical response of the floating laminated structure are clarified to provide important information regarding the optimal design of such structures. 相似文献
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In this paper we present a full-scale experimental field study of the effects of floater motion on a main bearing in a 6 MW turbine on a spar-type floating substructure. Floating wind turbines are necessary to access the full offshore wind power potential, but the characteristics of their operation leave a gap with respect to the rapidly developing empirical knowledge on operation of bottom-fixed turbines. Larger wind turbines are one of the most important contributions to reducing cost of energy, but challenge established drivetrain layouts, component size envelopes and analysis methods. We have used fibre optic strain sensor arrays to measure circumferential strain in the stationary ring in a main bearing. Strain data have been analysed in the time domain and the frequency domain and compared with data on environmental loads, floating turbine motion and turbine operation. The results show that the contribution to fluctuating strain from in-plane bending strain is two orders of magnitude larger than that from membrane strain. The fluctuating in-plane bending strain is the result of cyclic differences between blade bending moments, both in and out of the rotor plane, and is driven by wind loads and turbine rotation. The fluctuating membrane strain appears to be the result of both axial load from thrust, because of the bearing and roller geometry, and radial loads on the rotating bearing ring from total out-of-plane bending moments in the three blades. The membrane strain shows a contribution from slow-varying wind forces and floating turbine pitch motion. However, as the total fluctuating strain is dominated by the intrinsic effects of blade bending moments in these turbines, the relative effect of floater motion is very small. Mostly relevant for the intrinsic membrane strain, sum and difference frequencies appear in the measured responses as the result of nonlinear system behaviour. This is an important result with respect to turbine modelling and simulation, where global structural analyses and local drivetrain analyses are frequently decoupled. 相似文献
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船体型材加工的逆直线方法 总被引:1,自引:0,他引:1
本文阐述了逆直线基本大批量,讨论了数值计算方法,分析了逆直线计算系统的功能与结构,给出了实船计算结果,并介绍了逆直线画线机的机械原理、性能和技术指标。 相似文献
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与传统斜桩结构相比,全直桩结构完全以自身抗弯能力来承受水平荷载,在相同受力条件下存在桩径大、竖向承载力没有充分发挥、工程投资偏高的特点.针对该问题,提出一种新型含水平钢架的全直桩结构,以某工程系缆墩为例,采用空间模型进行计算分析,确定优化结构方案,并在该结构的桩基中间位置利用水平钢架与桩基进行连接.结果表明,增设水平钢... 相似文献
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针对东南亚地区采用中国标准的PHC管桩与英标的对接问题,基于英标对混凝土结构的一般规定,确定了英标应用于PHC管桩力学性能计算的方法,计算项目包括:材料强度、预应力损失、轴向允许最大工作压力、抗剪承载力、抗裂弯矩、极限弯矩,并将这些力学指标与我国常用标准的计算结果进行对比。对比结果表明:英标计算结果总预应力损失、有效预压应力接近;轴向允许最大工作压力偏小;抗剪承载力设计值、抗裂弯矩和极限弯矩设计值偏大。结果为海外工程中PHC管桩标准的使用提供了参考。 相似文献