【正文】 （ 4）使用內(nèi)在疲勞曲線的方法計(jì)算疲勞強(qiáng)度。 通過分析起重機(jī)載重表明，一些金屬材料受到較大動(dòng)態(tài)載，從而導(dǎo)致疲勞損傷的積累，其次是疲勞失效。這是從這個(gè)表中至少強(qiáng)度要件為 3 。 該項(xiàng)研究的一些金屬材料受到疲勞損傷的累積。 根據(jù)表 [ 4 ] ，有效應(yīng)力集中系數(shù)是接受的 KF = ， 給出了一個(gè)平均的價(jià)值，可承受的極限，作為 1ES? =67的強(qiáng)度創(chuàng)傷。起重機(jī)金屬制成的材料為合金鋼 09g2s，此材料有一個(gè)持久極限 120 MPa 和屈服強(qiáng)度 350 兆帕斯卡。如果初次分配每個(gè)獨(dú)立的任期有一個(gè)正態(tài)分布，那么載重周期為一年的平均數(shù)和標(biāo)準(zhǔn)偏差總數(shù)的都是平等的，大致為 423096 和650 。 每個(gè)月裝貨塊平均數(shù)值很快就獲得了，因此它是有可能找到適當(dāng)?shù)奶攸c(diǎn)， 如果采取中央極限周期，不僅為每月裝載量，而且也為每月或每年的裝載周期。應(yīng)該指出的是，直線圖的周期振幅與減少事后的非零平均數(shù)相等于直線圖為零時(shí)的平均數(shù)。第一是作為一獨(dú)特的振蕩講（閉 環(huán)），二是為一套加載周期期間一個(gè)運(yùn)行周期。首先，當(dāng)負(fù)載被提升時(shí)，壓力增加到最高值。 在 運(yùn)行 中，有可能的情況下，當(dāng)源自不同類型的負(fù)荷加載結(jié)合起來 。該金屬金工振蕩的特點(diǎn)是有兩個(gè)諧波在 2秒的過程當(dāng)中，這些已經(jīng)在前面的分析中獲得。這個(gè)電動(dòng)機(jī)以 。因此，以同時(shí)懸掛的速度，森林龍門式起重機(jī)受到較小的動(dòng)應(yīng)力與類似的一般用途的起重機(jī)相比而言。 第二個(gè)特點(diǎn)是物質(zhì)吊裝的加快導(dǎo)致低低效率。起重機(jī)的豎向載荷主要是由牽引力引起的。最大的壓縮應(yīng)力發(fā)生在變形的最大角度，在內(nèi)部看來 。頂端的桁架受到最大的壓縮應(yīng)力。 表 3 運(yùn)作周期的正太分布 3 .應(yīng)變測(cè)量 為了顯示大多數(shù)金屬的負(fù)載元素，并且確定一系列的壓力，事前做了靜態(tài)應(yīng)變測(cè)量。已正態(tài)分布漸近與均值和方差，確定抽樣數(shù)量的周期 v 而不依賴于整個(gè)的形式分布函數(shù)的 ()Ft ，（ 只對(duì)不同的格式分配進(jìn)行限制）。 設(shè) ? ?()nnF t P t???。使用運(yùn)行時(shí)間的起重機(jī)和評(píng)價(jià)周期時(shí)間，與實(shí)際增加一個(gè)數(shù)量的周期比，很容易得出比較大的誤差，因此，最好是作為如下。 每月搬運(yùn)價(jià)值的分布 Q（ t） ，被相對(duì)強(qiáng)度 q（ t）表示為 其中 Q是每年的裝載量的記錄存儲(chǔ)，是設(shè)計(jì)的最大存儲(chǔ)原木值 Q以百分比計(jì)算，其中為考察起重機(jī)等于 萬立方米每年， 和容積載重搬運(yùn)為 10 ％ 的起重機(jī)，得到的數(shù)據(jù)列在表 2 中，總量 56000立方米每年，用 K表示。 |機(jī)械故障分析 6（ 1999） 131141 表 1 搬運(yùn)強(qiáng)度（ %） 表 2 轉(zhuǎn)移儲(chǔ)存量 通過一年的觀察，從 118各搬運(yùn)值的觀察所了解到的數(shù)據(jù)進(jìn)行分析，并且有可能評(píng)價(jià)相關(guān)的搬運(yùn)強(qiáng) 度（噸）參考年度的裝載量的百分比。 搬運(yùn)強(qiáng)度 據(jù)了解，每年的搬運(yùn)強(qiáng)度是不規(guī)律的，不能被視為 一個(gè)平穩(wěn)過程。 如果每月從森林移動(dòng)的原木超過加工率，即是有一個(gè)原木存儲(chǔ)的倉庫，這個(gè)起重機(jī)期待的工作，也只是在原木加工的實(shí)際堆數(shù)在所供給原木數(shù)量的中心線以下； 一個(gè)起重機(jī)示意圖顯示在圖 1中 。 這種類型的起重機(jī)大約 1000 臺(tái)以上工作在俄羅斯森林工業(yè)的企業(yè)中。疲勞評(píng)估 。疲勞失效分析表明，一些元件的故障是自然的系統(tǒng)因素，并且不能被一些隨意的原因所解釋。106 and the slope m= for elements 1 and 3 and m= for element 2. The possible values of the element endurance limits presented above overlap the ranges of load amplitude with nonzero probability, which means that these elements are subjected to fatigue damage accumulation. Then it is possible to conclude that fatigue calculations for the elements are necessary as well as fatigue fife prediction. 6. Life prediction The study has that some elements of the metalwork are subject to fatigue damage predict fives we shall take advantage of intrinsic fatigue curves, which are detailed in [5]and [6]. Following the theory of intrinsic fatigue curves, we get lognormal life distribution densities for the inspected elements. The fife averages and standard deviations are fisted in Table 5. The lognormal fife distribution densities are shown in Fig. 7. It is seen from this table that the least fife is for element 3. Recollecting that an average number of load blocks for a year is equal to 12,719, it is clear that the average service fife of the crane before fatigue cracks appear in the welded elements is sufficient: the fife is years for element 1, years for element 2, and h years for element 3. However, the probability of failure of these elements within threefour years is not small and is in the range . These probabilities cannot be neglected, and services of design and maintenance should make efforts to extend the fife of the metalwork without permitting crack initiation and propagation. 7. Conclusions The analysis of the crane loading has shown that some elements of the metalwork are subjectedto large dynamic loads, which causes fatigue damage accumulation followed by fatigue procedure of fatigue hfe prediction proposed in this paper involves tour parts: (1) Analysis of the operation in practice and determination of the loading blocks for some period. (2) Rainflow cycle counting techniques for the calculation of loading cycles for a period of standard operation. (3) Selection of appropriate fatigue data for material. (4) Fatigue fife calculations using the intrinsic fatigue curves approach. The results of this investigation have been confirmed by the cases observed in practice, and the manufacturers have taken a decision about strengthening the fixed elements to extend their fatigue lives. 中文翻譯 龍門式起重機(jī)金屬材料的疲勞強(qiáng)度預(yù)測(cè) 摘要 內(nèi)在的疲勞曲線應(yīng)用到 龍門式起重機(jī)金屬材料的 疲勞壽命預(yù)測(cè)問題。the total volume of a processed load is on the average k= times more than the total volume of removal because of additional transfers. . Removal intensity It is known that the removal intensity for one year is irregular and cannot be considered as a stationary process. The study of the character of nonstationary flow of road trains at 23 enterprises Sverdlesprom for five years has shown that the monthly removal intensity even for one enterprise essentially varies from year to year. This is explained by the plex of various systematic and random effects which exert an influence on removal: weather conditions, conditions of roads and lorry fleet, etc. All wood b rought to the log store should, however, be processed within one year. Therefore, the less possibility of removing wood in the season between spring and autumn, the more intensively the wood removal should be performed in winter. While in winter the remova l intensity exceeds the processing considerably, in summer, in most cases, the more fulllength logs are processed than are taken out. From the analysis of 118 realizations of removal values observed for one year, it is possible to evaluate the relative r