古建筑木構(gòu)件內(nèi)部缺陷無損篩查方法研究
發(fā)布時間：2018-11-17 07:00
【摘要】：隨著科技的發(fā)展和實際的需要,無損檢測技術(shù)已逐步從機械工程等一般工業(yè)領(lǐng)域引入并應(yīng)用到木質(zhì)材料領(lǐng)域中來。木構(gòu)件的缺陷是影響木結(jié)構(gòu)古建筑安全性能的重要因素之一,在長期使用過程中由于木材本身特性,木構(gòu)件會因為有害生物侵蝕、含水率變化等因素而出現(xiàn)腐朽、孔洞、裂紋等缺陷,從而嚴(yán)重影響木構(gòu)件的使用性。在古建筑木結(jié)構(gòu)例行檢測、評估過程中,需要首先對各木構(gòu)件內(nèi)部缺陷情況進(jìn)行快速篩查,即利用無損檢測技術(shù)對木構(gòu)件內(nèi)部狀況進(jìn)行系統(tǒng)的排查,對內(nèi)部缺陷的有無和大小進(jìn)行初步判定和估算,為下一步內(nèi)部缺陷尺寸的精確檢測與木結(jié)構(gòu)安全性計算打下基礎(chǔ)。目前常用的古建筑木構(gòu)件內(nèi)部缺陷無損篩查方法主要包括用于初步篩查的敲擊法,用于驗證性篩查的應(yīng)力波法和微鉆阻力法等；存在的不足是準(zhǔn)確度差、檢測效率低。為了更好地滿足古建筑木構(gòu)件內(nèi)部缺陷篩查的要求并結(jié)合實際檢測工作中遇到的問題,本文對應(yīng)力波法、微鉆阻力法、敲擊法等古建筑木構(gòu)件內(nèi)部缺陷無損篩查方法進(jìn)行了進(jìn)一步深入研究,解決了應(yīng)力波法和微鉆阻力法檢測篩查過程中的一些關(guān)鍵問題；深入探索了敲擊法的機理,便捷了敲擊法的使用。論文主要研究內(nèi)容和創(chuàng)新如下。首先,針對目前國內(nèi)外廣泛用于古建筑木構(gòu)件內(nèi)部缺陷驗證性篩查的應(yīng)力波法和微鉆阻力法在實際運用中的問題,提出了古建筑木構(gòu)件應(yīng)力波臨界速度和一套結(jié)合這兩種檢測技術(shù)快速、有效篩查木構(gòu)件內(nèi)部缺陷的檢測方法。利用Fakopp應(yīng)力波檢測儀對古建筑木構(gòu)件常用的興安落葉松(Larix gmelinii)、杉木(Cunninghamia Lanceolata)、瓊楠(Beilschmiedia)進(jìn)行了應(yīng)力波波速的檢測和統(tǒng)計,再結(jié)合統(tǒng)計學(xué)原理確定了三種樹種的應(yīng)力波臨界速度,在一定程度上提高了應(yīng)力波法篩查古建筑木構(gòu)件內(nèi)部缺陷的效率和準(zhǔn)確度。同時將應(yīng)力波檢測和微鉆阻力檢測進(jìn)行了合理的聯(lián)合,先通過應(yīng)力波檢測確定木構(gòu)件內(nèi)部缺陷的有無、大致位置,再利用微鉆阻力檢測進(jìn)一步判斷缺陷的類型和尺寸。該方法能夠在損傷盡可能少的情況下對古建筑木構(gòu)件內(nèi)部缺陷進(jìn)行快速、有效的驗證性篩查。其次,針對敲擊法準(zhǔn)確度低、過度依靠檢測人員經(jīng)驗的不足,以提高其科學(xué)性和準(zhǔn)確度為目標(biāo),研究了利用敲擊聲音篩查木構(gòu)件內(nèi)部缺陷方法的檢測機理。通過試驗發(fā)現(xiàn)敲擊木構(gòu)件可能引起不同的振動,并將敲擊有內(nèi)部孔洞缺陷的木構(gòu)件的振動分為表面局部振動、整體振動和缺陷部位振動三種振動形式。通過機械振動模型簡化分別研究了三種振動的頻率、振幅等參數(shù),以及不同缺陷情況下振動參數(shù)的變化及規(guī)律；并且分析了將三種振動有效結(jié)合后來模擬實際敲擊有內(nèi)部空洞缺陷木構(gòu)件的各種情況作為木構(gòu)件內(nèi)部缺陷的陷篩依據(jù)。在前面敲擊檢測機理研究基礎(chǔ)上,分別對落葉松材的長方體和圓柱體兩種木構(gòu)件試件分別進(jìn)行了敲擊檢測試驗。通過后期加工出不同的孔洞來模擬木構(gòu)件的內(nèi)部缺陷,采集敲擊聲音信號并利用信號分析研究木構(gòu)件內(nèi)部缺陷對敲擊聲音的影響。通過統(tǒng)計分析發(fā)現(xiàn),聲音信號中均方根值、頻率等特征參數(shù)會隨著內(nèi)部缺陷的改變而發(fā)生相應(yīng)的變化且具有一定的規(guī)律。并且,敲擊試驗中聲音信號特征參數(shù)的變化規(guī)律與各簡化模型中的振動參數(shù)的變化規(guī)律在一定范圍內(nèi)是一致的,在一定程度上證實了敲擊檢測機理研究的正確性,從而可以通過這些特征篩查出內(nèi)部缺陷。綜合敲擊篩查木構(gòu)件內(nèi)部缺陷試驗結(jié)果,利用模糊模式識別法處理敲擊試驗數(shù)據(jù)。經(jīng)過對試驗數(shù)據(jù)樣本的規(guī)格化、模糊等價矩陣的建立及聚類計算分析,實現(xiàn)了木構(gòu)件內(nèi)部缺陷快速敲擊篩查的信號處理便捷化,降低了敲擊篩查木構(gòu)件內(nèi)部缺陷方法對檢測人員經(jīng)驗的依靠,同時提高了該方法的準(zhǔn)確度、科學(xué)性及實用性。最后,將研究成果應(yīng)用于北京市木結(jié)構(gòu)古建筑的實際檢測工作當(dāng)中,取得了較好的效果。
[Abstract]:With the development of science and technology and the actual need, the non-destructive testing technology has been gradually introduced and applied to the field of wood materials from the general industrial fields such as mechanical engineering. The defect of the wood component is one of the important factors that affect the safety performance of the wood structure ancient building. In the long-term use process, due to the characteristics of the wood, the wood component can be decayed, the hole, the crack and other defects due to the factors such as the harmful effect of the harmful organisms and the change of the water content. thereby seriously affecting the usability of the wood member. in that proces of routine detection and evaluation of the wood structure of the ancient building, the internal defect condition of each wood component needs to be quickly screened, namely, the internal condition of the wood component is checked by the non-destructive detection technology, and the presence or absence and the size of the internal defect are preliminarily determined and estimated, and lays a foundation for the accurate detection of the internal defect size and the calculation of the structural safety of the wood structure for the next step. The method for non-destructive screening of the internal defects of the conventional ancient building wood component mainly comprises a knocking method for preliminary screening, a stress wave method for verifying sexual screening and a micro-drilling resistance method, and the like, and the defect is that the accuracy is poor and the detection efficiency is low. In order to better meet the requirement of the internal defect screening of the ancient building and the problems encountered in the practical test, this paper makes a further study on the method of non-destructive screening of the internal defects of the ancient building, such as the stress wave method, the micro-drilling resistance method and the knocking method. The key problems in the detection and screening of the stress wave method and the micro-drill resistance method are solved, the mechanism of the knocking method is further explored, and the use of the knocking method is facilitated. The main contents and innovations of the paper are as follows. First, in view of the problems of the stress wave method and the micro-drill resistance method which are widely used at home and abroad for the verification of the internal defects of the ancient building and wood components, the critical speed of the stress wave and a set of combination of the two kinds of detection techniques are proposed. and the detection method of the internal defect of the wood component is effectively screened. The stress wave velocities of Larix gmelinii, Cunninghamia Lanceolata and Beilschmidia were measured and counted by using the Fakopp stress wave detector, and the critical velocity of the stress wave of the three species was determined by the statistical principle. and the efficiency and the accuracy of the internal defect of the building wood component are screened to a certain extent by the stress wave method. At the same time, the stress wave detection and the micro-drill resistance detection are combined reasonably, the existence and the approximate position of the internal defect of the wood member are determined by the stress wave detection, and the type and the size of the defect are further determined by using the micro-drill resistance detection. The method can quickly and effectively verify the internal defects of the ancient building wood component under the condition that the damage is as little as possible. Secondly, aiming at the low accuracy of the knocking method and the shortage of the experience of the detection personnel, the detection mechanism of the internal defect method of the wood component by using the knocking sound is studied. It is found that the knocking wood component can cause different vibration, and the vibration of the wood component with internal hole defects can be divided into three kinds of vibration modes, such as surface local vibration, integral vibration and defect part vibration. The frequency, amplitude and other parameters of the three kinds of vibration are studied by mechanical vibration model, and the variation and the law of the vibration parameters under different defects are studied. and the various conditions of effectively combining the three kinds of vibration and then simulating actual knocking with the internal cavity defect wood component are analyzed as the basis for the sinking of the internal defect of the wood component. On the basis of the research of the previous knocking detection mechanism, the test of the knocking test of the two kinds of wood component specimens of the cuboid and the cylinder of the larch wood was carried out, respectively. In this paper, the internal defect of wood component is simulated by machining different holes in the later stage, the sound signal is collected and the influence of the internal defect of the wood component on the knocking sound is studied by using the signal analysis. It is found that the characteristic parameters such as square root value and frequency in the sound signal can change with the change of the internal defect and have a certain rule. and the variation law of the characteristic parameters of the sound signal in the knocking test and the variation law of the vibration parameters in the simplified models are consistent within a certain range, and the correctness of the research on the detection mechanism of the knocking is confirmed to a certain extent, so that the internal defects can be screened through the characteristics. The results of the internal defect test of the wood component were screened by using the method of fuzzy pattern recognition and the test data were processed by fuzzy pattern recognition. After the normalization of the test data samples, the establishment of the fuzzy equivalent matrix and the calculation and analysis of the clustering, the signal processing of the internal defect rapid tap screening of the wood component is facilitated, the reliance of the internal defect method of the knocking screening wood component on the experience of the detection personnel is reduced, and meanwhile, the accuracy, the scientificity and the practicability of the method are improved. Finally, the research results are applied to the actual detection of the structure of the wood structure in Beijing, and the better results are obtained.
【學(xué)位授予單位】：北京林業(yè)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TU366.2;TU317
本文編號：2336879
[Abstract]:With the development of science and technology and the actual need, the non-destructive testing technology has been gradually introduced and applied to the field of wood materials from the general industrial fields such as mechanical engineering. The defect of the wood component is one of the important factors that affect the safety performance of the wood structure ancient building. In the long-term use process, due to the characteristics of the wood, the wood component can be decayed, the hole, the crack and other defects due to the factors such as the harmful effect of the harmful organisms and the change of the water content. thereby seriously affecting the usability of the wood member. in that proces of routine detection and evaluation of the wood structure of the ancient building, the internal defect condition of each wood component needs to be quickly screened, namely, the internal condition of the wood component is checked by the non-destructive detection technology, and the presence or absence and the size of the internal defect are preliminarily determined and estimated, and lays a foundation for the accurate detection of the internal defect size and the calculation of the structural safety of the wood structure for the next step. The method for non-destructive screening of the internal defects of the conventional ancient building wood component mainly comprises a knocking method for preliminary screening, a stress wave method for verifying sexual screening and a micro-drilling resistance method, and the like, and the defect is that the accuracy is poor and the detection efficiency is low. In order to better meet the requirement of the internal defect screening of the ancient building and the problems encountered in the practical test, this paper makes a further study on the method of non-destructive screening of the internal defects of the ancient building, such as the stress wave method, the micro-drilling resistance method and the knocking method. The key problems in the detection and screening of the stress wave method and the micro-drill resistance method are solved, the mechanism of the knocking method is further explored, and the use of the knocking method is facilitated. The main contents and innovations of the paper are as follows. First, in view of the problems of the stress wave method and the micro-drill resistance method which are widely used at home and abroad for the verification of the internal defects of the ancient building and wood components, the critical speed of the stress wave and a set of combination of the two kinds of detection techniques are proposed. and the detection method of the internal defect of the wood component is effectively screened. The stress wave velocities of Larix gmelinii, Cunninghamia Lanceolata and Beilschmidia were measured and counted by using the Fakopp stress wave detector, and the critical velocity of the stress wave of the three species was determined by the statistical principle. and the efficiency and the accuracy of the internal defect of the building wood component are screened to a certain extent by the stress wave method. At the same time, the stress wave detection and the micro-drill resistance detection are combined reasonably, the existence and the approximate position of the internal defect of the wood member are determined by the stress wave detection, and the type and the size of the defect are further determined by using the micro-drill resistance detection. The method can quickly and effectively verify the internal defects of the ancient building wood component under the condition that the damage is as little as possible. Secondly, aiming at the low accuracy of the knocking method and the shortage of the experience of the detection personnel, the detection mechanism of the internal defect method of the wood component by using the knocking sound is studied. It is found that the knocking wood component can cause different vibration, and the vibration of the wood component with internal hole defects can be divided into three kinds of vibration modes, such as surface local vibration, integral vibration and defect part vibration. The frequency, amplitude and other parameters of the three kinds of vibration are studied by mechanical vibration model, and the variation and the law of the vibration parameters under different defects are studied. and the various conditions of effectively combining the three kinds of vibration and then simulating actual knocking with the internal cavity defect wood component are analyzed as the basis for the sinking of the internal defect of the wood component. On the basis of the research of the previous knocking detection mechanism, the test of the knocking test of the two kinds of wood component specimens of the cuboid and the cylinder of the larch wood was carried out, respectively. In this paper, the internal defect of wood component is simulated by machining different holes in the later stage, the sound signal is collected and the influence of the internal defect of the wood component on the knocking sound is studied by using the signal analysis. It is found that the characteristic parameters such as square root value and frequency in the sound signal can change with the change of the internal defect and have a certain rule. and the variation law of the characteristic parameters of the sound signal in the knocking test and the variation law of the vibration parameters in the simplified models are consistent within a certain range, and the correctness of the research on the detection mechanism of the knocking is confirmed to a certain extent, so that the internal defects can be screened through the characteristics. The results of the internal defect test of the wood component were screened by using the method of fuzzy pattern recognition and the test data were processed by fuzzy pattern recognition. After the normalization of the test data samples, the establishment of the fuzzy equivalent matrix and the calculation and analysis of the clustering, the signal processing of the internal defect rapid tap screening of the wood component is facilitated, the reliance of the internal defect method of the knocking screening wood component on the experience of the detection personnel is reduced, and meanwhile, the accuracy, the scientificity and the practicability of the method are improved. Finally, the research results are applied to the actual detection of the structure of the wood structure in Beijing, and the better results are obtained.
【學(xué)位授予單位】：北京林業(yè)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TU366.2;TU317
【引證文獻(xiàn)】
相關(guān)期刊論文 前1條
1 張厚江;管成;文劍;;木質(zhì)材料無損檢測的應(yīng)用與研究進(jìn)展[J];林業(yè)工程學(xué)報;2016年06期
，本文編號：2336879
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