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1.
以一种新型3UPS+1RPU混联机床作为研究对象,对该混联机床在不同位姿下的刚度和动态特性进行研究。首先运用Solid Works对该混联机床建立三维实体模型,然后导入到有限元分析软件ANSYS Workbench进行刚度分析,找出了机床刚度的薄弱部位,通过比较得知位姿α下机床的刚度好于位姿β,并得出刚度随位姿变化的规律。然后进行模态分析,得到不同位姿下机床的1~6阶固有频率和振型,找出机床运动过程中易发生共振的位置;在模态分析的基础上,对该混联机床进行谐响应分析,得出动平台在X,Y,Z轴方向的位移响应曲线,找出该机床应该避开的敏感频率,并通过比较得知位姿α下的混联机床动态特性好于位姿β。因此得出结论:机床在加工零件的过程当中,应尽量避免达到极限位置(位姿β),从而使机床保持较高的刚度和较好的动态特性。  相似文献   

2.
通过实验模态测试与有限元理论分析相结合的方法,对金刚石圆盘锯的模态特性进行了研究,分别获取了金刚石圆盘锯的各阶固有频率,并用模态测试的实验数据验证、修正了有限元分析的理论模型,以准确的有限元理论模型为基础对金刚石圆盘锯的横梁部件进行了结构优化设计研究。减少了金刚石圆盘锯横梁的刚度冗余,在保证横梁静、动态性能略有提高的条件下,实现横梁的减重设计要求。  相似文献   

3.
为大幅度地提高嵌入式共固化复合材料阻尼结构固有频率,优化其刚度,以嵌入式共固化阻尼复合材料薄板为研究对象,利用有限元的方法对比分析了该结构薄板及十字加筋薄板固有振动特性,并得到了筋材薄壁宽度和高度对结构固有频率的影响规律。结果表明:加强筋大大提高了薄板结构的固有频率和刚度,加筋薄板结构的各阶固有频率随着加强筋高度增大而增加,其中一阶固有频率增加幅度最大。增加加强筋宽度可以提高薄板结构的各阶固有频率,随着加强筋宽度的增加,固有频率的增加幅度减小。  相似文献   

4.
为大幅度地提高嵌入式共固化复合材料阻尼结构固有频率,优化其刚度,以嵌入式共固化阻尼复合材料薄板为研究对象,利用有限元的方法对比分析了该结构薄板及十字加筋薄板固有振动特性,并得到了筋材薄壁宽度和高度对结构固有频率的影响规律。结果表明:加强筋大大提高了薄板结构的固有频率和刚度,加筋薄板结构的各阶固有频率随着加强筋高度增大而增加,其中一阶固有频率增加幅度最大。增加加强筋宽度可以提高薄板结构的各阶固有频率,随着加强筋宽度的增加,固有频率的增加幅度减小。  相似文献   

5.
建立三自由度高刚度机器人有限元模型并对其进行静、动态特性分析。对比分析制动器动作对机器人的刚度、固有频率和机器人在外力作用下的稳态响应的影响;对样机进行实验测试分析。结果表明:所提制动器结构方案能提高机器人的刚度和固有频率以及降低操作器末端的振幅,能够改善机器人工作时的动态特性。  相似文献   

6.
并联机床由于其强非线性的特性,且在不同位姿下它的振动特性是不同的。所以在通过试验测得并联机床在典型位姿下的振动信号,并对振动信号进行频域分析得到机床在典型位姿下的功率谱的基础上,应用功率谱分析初步得到机床的振动特性。再利用测试分析软件得到并联机床的在此位姿下的固有频率。最后用有限元分析软件ANSYS Workbench对机床的在典型位姿下进行有限元模态分析,并得到了并联机床在典型位姿下的振动特性。通过对比试验分析与有限元分析并进行灵敏度的分析得到了有限元模型的修改方向。对并联机床的优化提供了数据的支持。  相似文献   

7.
40MN钢丝缠绕多向模锻液压机机架有限元模态分析   总被引:1,自引:0,他引:1  
运用有限元软件ABAQUS6.8对40 MN钢丝缠绕多向模锻液压机机架进行了模态分析,得到前十阶固有频率和相应振型,分析了各阶振型对液压机性能的影响,同时研究了预紧系数对机架固有频率的影响.结果表明,机架整体刚度和质量分布均衡,最小固有频率16.3 Hz,钢丝缠绕预紧作用使机架固有频率提高约7%.为液压机结构动态设计及...  相似文献   

8.
针对机器人在加工应用中的弱刚性问题,对串联机器人打磨过程中的位姿进行优化以提高操作刚度。文章以ABB公司IRB6700六自由度串联机器人为研究对象,研究了该机器人在不同位姿下的刚度特性。首先以该型号机器人的连杆及结构参数,建立机器人各连杆坐标系,推导出其运动学方程及雅克比矩阵。其次忽略机器人臂杆刚度,建立了考虑关节刚度的机器人末端静刚度模型。最后研究了机器人在不同位姿下的刚度特性,以优化机器人末端刚度为目的,得到了该型号机器人在本打磨工况下的最优加工位姿。  相似文献   

9.
基于音圈电机驱动研制一种内嵌式快刀伺服装置,该装置结构紧凑,导向精度高,并运用Workbench进行了有限元仿真。静态分析得到气浮装置的应力应变分布情况,获得零部件最大变形量和最大应力值;模态分析得到气浮装置各阶固有频率和振型,并通过模态实验进行对比,验证有限元模型的合理性。分析结果表明:增加刚性支撑可提高快刀伺服装置固有频率,能有效避免"共振"现象发生。该设计方案能够实现大行程高刚度切削加工要求。  相似文献   

10.
床身是机床的重要基础件,它的动态特性和静态特性直接影响到机床的精度和稳定性.在设计阶段通过建立QMK008拉刀磨床床身的实体模型和有限元模型,基于有限元方法进行仿真计算,得到了原始设计方案床身的变形和模态.根据床身的结构特点和刚度要求对原始方案进行改进,通过有限元分析和对比,发现增加壁厚和筋板厚度床身刚度没有明显提高,采用米字型筋板可以提高床身的静刚度和狭长形床身的固有频率,增加地脚螺栓个数对于提高床身动静刚度也有明显作用.  相似文献   

11.
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.  相似文献   

12.
The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.  相似文献   

13.
Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.  相似文献   

14.
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.  相似文献   

15.
韩磊 《腐蚀与防护》2015,36(1):84-90,94
综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。  相似文献   

16.
The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.  相似文献   

17.
On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes' collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.  相似文献   

18.
Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.  相似文献   

19.
A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.  相似文献   

20.
Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.  相似文献   

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