共查询到19条相似文献,搜索用时 109 毫秒
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开缝衬套、导弹舱壳等航空薄壁件采用切削加工或传统的滚弯技术很难保证制造精度,柔性滚弯技术很好地解决了此问题.本文简单介绍了双轴柔性滚弯并将其与传统的三轴滚弯进行了比较,推导了异形截面滚弯的理论模型,详细阐述了数控系统的硬件构成及软件实现.利用本系统可以加工出多种直径的圆筒件以及简单的异形截面零件. 相似文献
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《机械制造与自动化》2017,(5):42-44
柔性滚弯成形技术主要用于制造形状多样化、生产批量小的复杂薄壁曲面制件,广泛运用于飞机、船舶、火箭等运载工具。总结了柔性滚弯成形技术在国内外的研究现状,介绍了刚性辊滚压橡胶垫的单轴柔性滚弯成形技术;刚性辊和柔性辊相互作用或者双柔性辊相互作用的双轴柔性滚弯成形技术;可弯曲、可调节的三柔性辊相互作用的曲面连续成形技术。对新型工艺技术的基本原理以及工艺特点进行了分析和总结。 相似文献
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基于有限元分析的二轴柔性滚弯过程影响因素的研究 总被引:2,自引:0,他引:2
利用弹性介质对钣金件进行二轴柔性滚弯成形是一种先进的钣金制造工艺,将弹性介质(聚氨酯橡胶)的冲压优势和传统滚弯原理结合,成为钣金成形领域的一个新的发展方向。本文利用有限元软件MARC建立二轴柔性滚弯过程的有限元分析模型,成功的模拟了板料滚弯成形及回弹的加工过程,对工件滚弯成形过程的主要影响因素进行了分析,给出了压入深度、柔性层厚度、刚性滚轴半径、材料性能与回弹后曲率半径的关系。分析结果表明,有限元模拟对滚弯过程的工艺参数选取有着一定的指导意义。 相似文献
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根据车体的结构属性和质量分布将其考虑为多段变截面欧拉梁,建立包含车体一阶垂弯模态的车辆垂向动力学模型,研究车体一阶垂弯振型的节点位置对高速列车振动舒适度的影响,提出改善车体弹性振动的措施。基于变截面欧拉梁模型分析车体各截面的质量和抗弯刚度分布对模态振型的影响,发现不同截面之间的抗弯刚度和质量分布对整体模态振型影响显著,提高车体中部结构的抗弯刚度并减小其质量,可以增大节点间距和提高模态频率,而传统均直等截面梁模型则不能准确描述振型的幅值和节点位置。采用频域分析方法计算车辆在轨道随机激励下的振动响应,将车体垂弯振型节点调整到转向架二系上方附近时,车体的弹性振动水平显著降低,在车速为300 km/h时车辆舒适度指标可降低50%。 相似文献
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An optimized distribution of tilt angles for tomography of specimens of non-circular cross-section is derived and tested with reconstructions of a phantom model. 相似文献
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曹玉华 《机械制造与自动化》2004,33(6):109-111,116
分析了直线电动机用于机床进给系统的结构特点,针对非圆截面加工的特殊要求,设计了用于数控机床进给系统的直线电动机驱动部件。 相似文献
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A general three-dimensional (3D) anisotropic hexagonal model of columnar structure with non-uniform strut morphology is developed. This model covers several types of cellular structure such as two-dimensional (2D) hexagonal and square honeycombs, and 3D hexagonal and rhombic cellular materials of rod-like columnar structure. The effective elastic constants are determined taking account of bending, axial, and shear deformations of the struts. Unlike the theoretical work of other investigators for 2D honeycombs, considering bending, axial and shearing deformations of struts, the present model not only produces transverse isotropy for regular hexagonal columnar structure but also provides a consistent Poisson's ratio when applied to a square honeycomb. The effect of tapered strut morphology on the elastic properties of cellular structures is investigated. For the general hexagonal columnar structures, the bending compliance is the dominant function for the in-plane elastic constants of 2D and 3D structures (excluding the in-plane shear modulus of rhombic structures) and the out-of-plane shear moduli of 3D structures, but the axial compliance is dominant for the in-plane shear modulus of 2D and 3D rhombic structures and the out-of-plane Young's modulus of 3D structures. For cellular materials with the same relative density, the presence of taper increases values of the effective Young's and shear moduli for which the bending compliance is dominant, but decreases those for which the axial compliance is dominant. It is found that the effective elastic properties of cellular materials are dependent not only on the relative density but also on strut morphology both in cross-section geometry and its variation along the strut length which the present model takes account of. These results illustrate the importance of the strut morphology in calculating the effective elastic properties of cellular materials. 相似文献
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Bend-stretch forming is a cold-forming operation used to bend initially straight aluminum extrusions. The process consists of bending the parts over a curved die in the presence of axial tension. Higher tensions reduce the springback of the part but can induce relatively large, permanent cross-sectional distortions. This work presents an efficient formulation to predict the cross-sectional distortion of extrusions with relatively arbitrary, thin-walled cross-section. The results show good agreement with calculations for simple tubular sections and experimental results in the literature. The numerical implementation has short computer run times and should be useful in the design of extrusion cross-sections and in the optimization of the process variables. 相似文献
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根据衍生式数控系统的原理,采用压电陶瓷执行器驱动的直线伺服执行机构为衍生模块,扩展普通数控车床,使之具备除通用数控车削功能外,还能加工非圆截面的功能,根据非圆截面形状数据及其相应的控制程序加工出所需的非圆截面,在实际加工前通过仿真模拟检验非圆截面加工程序是否正确,保证加工的准确性。 相似文献
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非圆齿轮传动具有广泛的应用场景。针对非圆齿轮传动,采用齿轮啮合原理和材料力学等原理及方法,提出了大重合度非圆齿轮设计方法。探讨了非圆齿轮传动原理和节曲线构建方法,计算了其节曲线曲率半径和重合度方程。建立了不同重合度非圆齿轮轮齿时变啮合刚度与载荷分配率计算模型,推导了不同重合度非圆齿轮齿根弯曲应力方程。探讨了不同结构参数下非圆齿轮副重合度、时变啮合刚度、时变载荷分配率及齿根弯曲应力变化规律,确定了轮齿所受最大载荷位置。开展了不同重合度非圆齿轮齿根弯曲应力仿真分析和实验测量,与理论计算结果进行了对比分析,最大误差分别约为4.8%和5.9%,验证了理论方法的合理性与正确性,为大重合度非圆齿轮传动的工程应用奠定了基础。 相似文献