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单榫头叶片精锻三维热力耦合有限元模拟 总被引:4,自引:0,他引:4
叶片是航空发动机中一类量大面广的重要零件,精锻是叶片锻造的发展趋势。叶片精锻过程属于高温大变 形过程,坯料与模具和环境之间存在着热交换,同时塑性变形功以及坯料和模具间的摩擦功不断转化为热能,其结 果促使坯料内的温度场不断发生变化,进而影响到坯料的变形行为,并进一步影响锻件的微观组织及机械性能。因 此,本文采用三维热力耦合有限元数值模拟技术,利用自行开发的叶片锻造过程三维刚粘塑性热力耦合有限元模拟 系统对单榫头叶片精锻过程进行了模拟分析,研究了叶片精锻成形规律。该研究对制定叶片精锻工艺以及发展叶 片精锻技术具有重要的理论意义和实用价值。 相似文献
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针对传统叶片锻造转角设计方法的局限性,通过构建基于知识的叶片锻造转角设计的总体框架,并对叶片锻造转角设计的知识来源进行获取(锻造转角确定工艺原则、数值模拟分析数据),并对叶片锻造转角的设计过程创建了新的知识建模。依据知识工程技术和产品设计开发技术,通过集成行业专家的设计经验和知识,对汽轮机叶片锻造转角的设计进行研究,提出了汽轮机叶片锻造转角设计的新方法,增强产品的开发能力,加快设计进程,提高叶片设计效率。 相似文献
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基于Simufact.Forming径向锻造模块对某叶片毛坯锻造成形过程进行数值模拟分析,研究了径向锻坯到叶片模锻的成型过程,获得了叶片锻坯在径向锻造过程中等效应变以及锻流线分布规律。深入分析锻坯锻透性,并对径锻成形过程进行理论计算和试验验证。结果表明:适当提高相对压下率能使锻坯变形均匀,采用拉打径向锻造方式能够有效保证锻坯成型的尺寸精度,得到的叶片锻坯模锻充型效果较好,飞边分布均匀,锻坯心部等效应力在锻打时有规律地发生波动,旋转锻打使金属材料沿周向流动,锻流线的扭转角与旋转角相一致,锻坯质量较好,无明显缺陷。 相似文献
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针对汽轮机叶片倒圆处曲面造型困难,叶身与叶根连接处转接R的设计难度大、几何精度要求高等问题,以叶片锻件为研究对象,通过滚动球模型进行叶片过渡圆角的设计,并构建基于Deform的叶片模锻有限元模型。应用数值模拟技术对叶片过渡圆角进行叶片锻造成型过程分析,得到叶片转接R处应力应变的模拟结果,比较不同叶片转接R条件下最大成型应力、锻造载荷、侧向力的变化,及模具受到的影响,对叶片转接R的大小和锻模的设计具有参考价值。 相似文献
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叶片锻造技术的现状与发展趋势探讨 总被引:2,自引:0,他引:2
通过分析叶片锻造成形技术的现状 ,对其发展趋势进行了探讨。介绍了叶片锻造过程的计算机模拟技术、智能技术在叶片锻造工艺设计中的应用前景以及叶片锻模 CAD/ CAM,并对存在的一些问题进行了详细的讨论 相似文献
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锻压变形工艺参数对锻模模膛充填性的研究 总被引:2,自引:0,他引:2
针对锻模模膛充填困难的特点,以2A12铝合金为研究对象,以棒料模锻后的充填高度为控制目标,采用有限元数值模拟和虚拟试验相结合的方法,模拟模锻过程,分析坯料的变形行为,讨论温度、应变、应变速率等的变化和分布情况,研究不同工艺参数对模膛充填性的影响。结合正交试验与有限元数值模拟技术,对模膛充填性的影响因素进行研究,得出模膛充填能力影响因素的主次顺序、各因素的影响趋势及最优搭配方案。同时以纯铅为模拟材料,对模锻过程进行物理模拟。 相似文献
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Optimization of the forging of aerofoil blade using the finite element method and fuzzy-Pareto based genetic algorithm 总被引:1,自引:0,他引:1
V. Alimirzaloo M. H. Sadeghi F. R. Biglari 《Journal of Mechanical Science and Technology》2012,26(6):1801-1810
In this research non-isothermal forging process of an aerofoil blade was simulated using 3-dimentional finite element method. Then an optimization approach integrated with the finite element method has been applied to optimize the blade forging process. Preform shape and angular position of the die parting line were optimized in order to minimize the flash volume, strain non-uniformity and lateral forces generated during the forging operation. The optimization method includes the finite element approach and the response surface method for the formulation of the objective functions. Using the multi-objective genetic algorithm, Pareto front of global optimal solutions was generated. Then a fuzzy-based membership value assignment method was used to select the best compromise solution. The simulation of the blade forging process was verified by experimental test. Results show that the numerical results and experimental tests have a good agreement. Waste material and lateral forces generated during the forging operation is decreased with optimization method significantly. Therefore the proposed approach is an appropriate method for multi-objective optimization of the forging process of aerofoil blades. 相似文献
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T. S. Yang N. C. Hwang S. Y. Chang 《Journal of Mechanical Science and Technology》2007,21(10):1566-1572
The manufacture of gears by applying hot or cold bulk forming processes is a quite widespread production method due to its
well-known basic advantages such as material and time cost reduction and the increased strength of the teeth. However, the
associated process planning and tool design are more complicated. In the precision forging of gears, the workpiece volume,
the die design, the power requirement and careful processing are more critical than traditional forging technology. For complete
filling up, predicting the power requirement is an important feature of the near net-shape forging process. In this paper,
a finite element analysis is utilized to investigate the material properties such as yielding stress, strength coefficient
and strain hardening exponent effects on forming load and maximum effective stress. The adductive network was then applied
to synthesize the data set obtained from the numerical simulation. The predicted results of the maximum forging load and maximum
equivalent stress of bevel gear forging from the prediction model are consistent with the results obtained from FEM simulation
quite well. After employing the prediction model one can provide valuable references in prediction of the maximum forging
load and maximum equivalent stress of bevel gear forging under a suitable range of material parameters. 相似文献
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Qiu Ma Zhong-qin Lin Zhong-qi Yu 《The International Journal of Advanced Manufacturing Technology》2009,40(3-4):253-260
A numerical simulation of multi-stage heavy forging process using the finite element method (FEM) is presented in this study. The process of heavy forging is highly non-linear, where both microstructure and boundary conditions are altered by plastic deformation during forming. Therefore, it is necessary to understand the problem of plastic deformation in heavy forging. In order to investigate deformation behavior and microstructure evolution in heavy forging, a constitutive equation considering the effects of strain hardening and dynamic softening of the IN718 alloy is built. The constitutive equation and microstructure models are implemented into the finite element code to simulate deformation behavior and microstructure evolution in the rotary forging of heavy container head. As a result, variations of flow stress, effective strain, temperature, damage, and grain size in every stage are predicted. 相似文献
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Z. H. Chen C. Y. Tang T. C. Lee L. C. Chan 《International Journal of Mechanical Sciences》2002,44(7):1309-1333
In order to achieve a more intensive understanding of the forming mechanism of the fine-blanking process, a numerical simulation has been carried out by using a mixed displacement/pressure (u/p) finite element method. According to the special requirement of the fine-blanking technique, the major process attributes, such as the vee-ring, the ejector and the edge radii of tools, have been taken into account in the finite element model. The punch–die clearance was set to 0.5% of the thickness of the workpiece. To verify the effectiveness of the simulation, the equivalent strain on the sheared surface of a SS400 steel specimen has been determined experimentally. The experimental values of the equivalent strain have been estimated by measuring the relative displacements of the local grids pre-etched on the meridian plane of the specimen. The results of the finite element simulation are in proper agreement with the experimental findings. The distributions of the shear stress and the equivalent plastic strain have been computed for discussion. Moreover, a diagram of the blanking force versus the punch penetration has also been constructed. In order to investigate the fracture mechanism in the fine-blanking process, the concept of damage mechanics has been applied. By using a void growth model, the evolution of damage at different stages of the fine-blanking has been evaluated. It has been realized that the compressive hydrostatic stress built up by the fine-blanking fixture plays an important role to suppress the initiation of macrocracks. 相似文献
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Do-Jin Cha Dong-Kwon Kim Jong-Rae Cho Won-Byong Bae 《International Journal of Precision Engineering and Manufacturing》2011,12(2):331-336
The Waspaloy, a Ni-based superalloy, has been widely used for forging material of gas turbine disk since it requires the high
tensile strength at high temperature and good resistance to low cycle fatigue. The purpose of this study is to develop a forging
process of turbine disk that satisfies the hot deformation characteristics of Waspaloy. Generally, the hot forging of superalloy
has been subjected to isothermal forging since the available temperature range of forging is narrow. However, the non-isothermal
forging was used to make a turbine disk in this study. Therefore, the analyses of temperature variation and deformation behavior
of the material were important to obtain the sound forging products. The hot compression test was carried out to know formability
at high temperature and microstructure evolution during hot deformation. In order to define the optimum forging conditions
including material temperature, strain rate, strain, microstructure evolution and forging load, the commercial finite element
analysis code was used to simulate the forging procedure of turbine disk. The hot forged turbine disk was heat-treated for
obtaining the high temperature properties. The cut-off tests on the heat-treated forged disks were carried out. Experimental
results were compared with the simulation results by FE analysis. Test results were in good agreement with the simulations.
This study shows that the superalloy turbine disk can be manufactured by the semi-closed die forging. 相似文献