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本文介绍了电液伺服激振台的工作原理,着重讨论了在正弦激励信号下电液伺服加载系统极限工作范围的确定方法,及其应用实例,它对激振加载实验的设计,调试及测试结果分析都具有一定意义。 相似文献
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在高频重载电液伺服加载系统中,其安装机架的变形和振动会限制系统的频宽,尤其当进行高频简谐加载时,产生的冲击载荷使机架发生谐振,加剧了机架的变形和振动,严重时甚至破坏系统的稳定性。以采用十字形横梁为机架的单摆负载电液伺服加载系统为例,利用Abaqus软件对机架结构进行了模态及谐响应分析,通过分析机架在油缸简谐激振力作用下的谐振特性,获得机架各部分结构振动的强弱分布及抗振薄弱区位置,由此提出了提高机架刚度的抗振加固方案,将原十字形横梁改为对角结构,在抗振薄弱区增加筋板,构建三角结构。优化后的方案使机架一阶固有频率从141 Hz提高到190Hz,满足了系统的频宽要求。 相似文献
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根据结晶器激振系统结构组成,建立了伺服放大器、电液伺服阀、差动液压缸等组件的数学模型,利用仿真软件MATLAB对结晶器振动系统进行频域、时域的仿真分析,以确定系统的稳定性、快速性,并通过扫频法对结晶器激振系统的动态特性进行了测试评估,提出了合理的措施以提高系统性能. 相似文献
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高频激振时效技术的研究 总被引:1,自引:0,他引:1
常规振动时效的大振幅常常会导致被处理工件的疲劳损伤,这一点局限了其推广和应用。本文探讨了一种微幅激振时效的帮方法,即高频激振时效法。主要研究内容包括:高频激振时效的机理,高频激振时效装置以及高频激振时效结果的金相分析。实验研究及金相分析结果表明,高频激振时效技术是一种有效的振动时效新方法。 相似文献
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The stability fields of various sulfide phases that form on Fe-Cr, Fe-Ni, Ni-Cr, and Fe-Cr-Ni alloys have been developed as a function of temperature and the partial pressure of sulfur. The calculated stability fields in the ternary A-B-S system are displayed on plots of log
vs. the conjugate extensive variable (nA/nA–nB), which provides a better framework for following the sulfidation of Fe-Cr-Ni alloys at high temperatures. Experimental and estimated thermodynamic data were used in developing the sulfur potential diagrams. Current models and correlations were employed to estimate the unknown thermodynamic behavior of solid solutions of sulfides and to supplement the incomplete phase-diagram data of geophysical literature. These constructed stability field diagrams are in excellent agreement with the sulfide phases and compositions determined experimentally during the sulfidation of SAE 310 stainless steel. The sulfur potential plots appear to be very useful in predicting and correlating the sulfidation of commercial alloys.Nomenclature
a
i
Activity of componenti
- G
0
Standard Gibb's free energy change
- G
M
Integral molar free energy of mixing
- G
i
0
Partial molar free energy of mixing of componenti
- H
Standard enthalpy change
- H
i
Partial molar enthalpy (heat) of mixing of componenti
- H
M
Integral molar enthalpy (heat) of mixing
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K
Equilibrium constant
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n
i
Moles of componenti
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p
s
2
Partial pressure of diatomic sulfur
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R
Gas constant
- S
i
Partial molar entropy of mixing of componenti
- S
M
Integral molar entropy of mixing
- S
0
Standard entropy change
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T orK
Absolute temperature
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X
i
Mole fraction of componenti
- i
Activity coefficient of componenti
- i
Relative chemical potential of componenti 相似文献
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JIANG Guochang ZHANG Xiaobing XU Kuangdi Shanghai University of Technology Shanghai China 《金属学报(英文版)》1992,5(12):476-482
Expressing the excess partial molar free energies and integral excess free energy as poly-nome of the composition,then the parameters in the expression of excess partial molarfree energy of C were evaluated based on:the excess partial free energy of C in C-Fe bi-nary alloy:the integral excess free energy of Fe-X binary alloy:the C saturation curveand the iso-activity curve of C (α_c=0.025) in the ternary system.Then the activitycoefficient of X was evaluated with the so-called “I-D” method,by which the componentactivities of every element in the whole molten ternary alloy can be evaluated,and theresults are in good agreement with literature data based on experiment. 相似文献
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介绍了锌沸腾焙烧专家系统的结构与功能,锌沸腾焙烧的专家知识与推理,重点分析了该专家系统的主要特点,包括改造的黑板系统、动态数据交换、数学模型以及多任务机制等。该系统应用于现场的实际生产,取得了良好的效果 相似文献
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张君艳 《锻压装备与制造技术》2017,52(5)
针对液压机的液压回路控制部分进行了PLC控制系统改造,给出了PLC的输入输出地址表、PLC接线图以及软件程序,调试运行后,不仅提高了其保压控制性能,而且大大提高了系统的可靠性、稳定性和生产效率。 相似文献