Fatigue damage once invalidated railway bridge, fatigue crack ever resulted in collapse of artesian well desk in ocean.

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An advanced branch and bound method which reduces the computer resolving time enormously and leads the reliability research of large-scale spatial frame structural systems close to practical use is presented on condition that the same computation accuracy is ensured.

導(dǎo)出了大型空間剛架結(jié)構(gòu)系統(tǒng)某梁元斷面達(dá)到塑性屈服極限時的修正剛度矩陣和相應(yīng)的等效節(jié)點力向量手机在线看永久AV片免费无毒；提出了在保證同等計算精度的條件下免费无码国产在线观看91，可成倍地減少運算時間的改進(jìn)分枝限界方法可以免费看黄色网站，使大型空間剛架結(jié)構(gòu)系統(tǒng)的可靠性研究向?qū)嵱没~進(jìn)最大黄色网站一级在线；本文開發(fā)出可自動生成失效衡準(zhǔn)久久有线视频，自動選擇主要失效形式在线看羞羞视频网站，追蹤失效過程的計算機(jī)程序。

The effect of tribology factors on bearing vibration is studied experimentally. AR model and WPT are used to processing the normal arid abnormal signals. The results are as follows:1. The vibration of ball bearings is caused by the tribology action of contact pairs of ball and ring races and has the essential of tribo-dynamics. Any factors affecting the tribology characteristics of contact pairs will affect vibration and noise of bearings consequently.2. Vibration characteristics of bearing keep almostly unchanged with the increasing of axial load expecting the increasing of nature frequencies. When radial load increasing with axial load unchanged, nature frequencies keep unchanged but some new vibration peaks appears in the spectrum.3. Vibration amplitudes are damped and nature frequency are enhanced with sufficient lubrication. Vibration and noise of bearings increase obviously and roar can happen and the contact surfaces scratch slightly under insufficient and unclean lubrication state. Bearing will be disabled in a few minutes without any lubrication.4. Bearing vibration is unstable under low speed. With the speed increasing, the vibration become stable and natural frequencies increase slightly but the amplitudes increase apparently.5. Bearing vibration can be excited only by some harmonics ofwaviness without lubrication and by all harmonics with lubrication based on the theoretical analysis.6. The nature frequencies of ball bearings decrease with the increasing sizes. When international clearance increasing, nature frequencies decrease in radial and increase in axial and angular and the amplitudes increase in radial and decrease in axial and angular. When the number of balls increasing, nature frequencies increase and amplitudes decrease. When the pitch diameter increasing, axial nature frequency increase and others nearly keep no change. When outer race groove curvature radius increasing, nature frequencies increase in radial and decrease in axial and angular and amplitudes keep no change in radial and increase in axial and angular. When inner race groove curvature radius increasing, nature frequencies decrease and amplitudes increase.7. The distortion in amplitude and frequency components of bearing vibration signals picked up by the present probe measurement method is founded and right conclusions cannot be achieved by the signals. When accelerometer is rigidly screwed with steel stud onto a flat outer surface of a ball bearing, vibration signal can be got without distortion and the reliability of research on bearing vibration is assured.8. AR model is suitable for large samples of bearing vibration signals, square root of length of samples can be used as the upper limitation of order determination and the FPE order selection criterion is effective. Many advantages of AR spectrum are founded over the classical based on FFT.9. Time-Frequency analysis is necessary for abnormal noise of ball bearings. WPT overcomes the principle shortcomings of STFT and proved to be a best tool to process the abnormal signals.

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Tear-down analysis indicates that for VRLA battery, water loss ,negative plate sulphation and positive active material softening are the main causes of failure.

通過對失效的VRLA電池的解剖分析免费黄在线看，電池失水、負(fù)極板硫酸鹽化和正極板活性物質(zhì)軟化是導(dǎo)致VRLA失效的主要原因A片免费网在线观看网址入口，介紹了一種使失效電池容量恢復(fù)的方法国产黄色片一级片，并對該方法的有效性機(jī)理進(jìn)行了簡單分析。

Anything which invalidates the input sequence will invalidate the match results.

任何使輸入序列失效的事件都會使匹配結(jié)果失效免费观看黄、色一级视频。

Causing the omens of boasters to fail, Making fools out of diviners, Causing wise men to draw back And turning their knowledge into foolishness

賽44：25 使說假話的兆頭失效欧美视频自拍偷拍、使占卜的癲狂、使智慧人退后3d全彩无码无遮挡肉肉、使他的知識變?yōu)橛拮尽?/p>

Causing the omens of boasters to fail, Making fools out of diviners, Causing wise men to draw back And turning their knowledge into foolishness

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Combined with the macro-morphology appearance analysis and working conditions of failure casing, the paper reached a conclusion that it is due to the impact and friction which come from the drill tools made the fatigue cracks formation on the casing thread root, and eventually leading to casing rupture failure, the material defects in failure casing accelerated crack initiation and growth.

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It is clarified for the first time that the thermal fatigue failure of solder joint is actually a creep strain low cycle fatigue failure, and a physical model for creep fatigue crack propagation has been proposed. It was pointed out that creep strain increases in the high stress area ahead of the tip of thermal fatigue crack, results on one hand that the slide of crack tip increase, inactivation more serious and crack close length increases, the other hand, that intergranular crack exists, whose direction will affect the fatigue crack propagating.

本文首次闡明了焊點的熱循環(huán)失效本質(zhì)上是以焊點內(nèi)循環(huán)蠕變?yōu)橹饕獞?yīng)變的低周疲勞失效www.色呦呦，并在此基礎(chǔ)上提出了蠕變疲勞裂紋擴(kuò)展的物理模型俄欧美激情A片在线观看，指出熱循環(huán)裂紋前端的高應(yīng)力區(qū)內(nèi)，蠕變加劇一级做a爱片久久毛片看看精品，使裂紋前端滑移增加美女互摸互慰AV网站在线观看，裂紋鈍化加劇，導(dǎo)致隨后的裂紋閉合擴(kuò)展長度增加；同時蠕變也使裂紋前端的高應(yīng)力區(qū)出現(xiàn)晶間裂紋暴力强奸黄色网站有效，蠕變沿晶裂紋對主裂紋擴(kuò)展的影響取決于沿晶裂紋的連接方向日韩黄色视频毛片。

It is shown that the contact interaction enables bottom drillstring to whirl backward, and then an alternate bending stress with higher frequency is produced. So the drillstring fatigue failure could be accelerated. At the same time, a quite strong wallop force of high frequency is produced on the contacting point, and the contacting zone is next to the screw coupling of drill collars. It will easily result in the failure of screw couplings. The research results provide theoretical basis for the prevention of drillstring failure.

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DEACTIVATE POPUP：使DEFINEPOPUP創(chuàng)建的菜單失效

DEACTIVATE MENU 使一個用戶自定義菜單欄失效,并將它從屏幕上移去,但并不從內(nèi)存中刪除菜單欄的定 義 | DEACTIVATE POPUP 使DEFINEPOPUP創(chuàng)建的菜單失效 | DEFINE MENU 創(chuàng)建菜單欄

DEACTIVATE MENU：使一個用戶自定義菜單欄失效,并將它從屏幕上移去,但并不從內(nèi)存中刪除菜單欄的定 義

CREATE MENU 在ViualFoxPro中打開菜單設(shè)計器 | DEACTIVATE MENU 使一個用戶自定義菜單欄失效,并將它從屏幕上移去,但并不從內(nèi)存中刪除菜單欄的定 義 | DEACTIVATE POPUP 使DEFINEPOPUP創(chuàng)建的菜單失效

deactivated：使失效

deactivated 去活化 | deactivated 使失效 | deactivatedeactivated 使不活動

deactivated：去活化/使不活動/使失效

deactivate /解除動員/復(fù)員/使無效/使不活動/ | deactivated /去活化/使不活動/使失效/ | deactivation /無動化/

invalidate：使失效

identification and traceability maintenance and replacement 識別和可追溯性維護(hù)與替換 | invalidate 使失效 | market survey 市場調(diào)研

vitiator：使失效的人

vitiablevoidable 可使無效的 | vitiator 使失效的人 | vitiator 損害的人

vitiator：損害的人/使失效的人

vitiate /損壞/ | vitiator /損害的人/使失效的人/ | viticultural /葡萄栽培的/

Inks, banknote invalidating：油墨,用于使鈔票失效

3242125 Inks, fingerprinting 印油,用于按手印 | 3242126 Inks, banknote invalidating 油墨,用于使鈔票失效 | 3242127 Inks, penetrant, material testing 油墨,可滲透的,用于原材料測試

vitiating：使失效

實質(zhì)性損害賠償金 (-:-) sbstantial damages | 使失效 (-:-) vitiating | 使無效 (-:-) nullify

Vitiating Factors：使失效的因素

Terms of a Contract合同條款 | Vitiating Factors使失效的因素 | Mistake錯誤