螺栓構件由於其施工的方便性在工程上使用的非常廣泛，特別是高強度螺栓，有著良好的耐反覆衝擊特性，足夠的強度可以符合土木工程的需要，但螺栓也有可能因為外在的原因而產生鬆脫，當其預力不足就可能會產生許多風險，本文旨在探討對螺栓敲擊並利用其動態行為與音響放射行為是否能即時檢測出預力不足。
本研究針對螺栓接合結構動態與聲學特性進行研究，研究方法是透過對鋼板-螺栓接合模型施加衝擊並搭配振動計、錄音設備，研究螺栓在不同的預力損失率時，其所產生的振動與音響放射行為是否會有所不同，接著更換螺栓為不鏽鋼螺栓，探討當螺栓材質變化時，行為是否也會有所變化。
對於螺栓的動態行為，並透過有限元素法得知，實驗模型的振動行為主要由前兩個模態控制，而且螺栓材質並不會對模態頻率產生太大影響。使用兩種不同螺栓都可以觀察到兩個模態的頻率都會隨著預力損失率的增加而減少，但是其中皆不會有明顯的躍升，並不適合做為預力參考指標；音響放射時先將訊號進行FFT在對其分析，則可以觀察三個基頻皆會有與動態相似的行為，頻率都會隨著預力損失率的增加而減少，唯一不同的是在預力損失增加到一定程度時，其頻率偏移率會突然的增加，其中高強度螺栓在較低頻率時頻率的偏移會在較低預力損失率時發生，因此可以更早地對螺栓預力不足一事進行預警，即早進行相關措施，更適合作為螺栓預力指標。

This research focuses on the dynamic and acoustic characteristics of the bolted joint structure. The research method is to study the vibration and the vibration of the bolt at different pre-force loss rates by applying an impact to the steel plate-bolt joint model with a vibrometer and recording equipment. Whether the sound radiation behavior will be different, then change the bolt material to stainless steel bolts, and explore whether the behavior will also change when the bolt material changes.
Regarding the dynamic behavior of the bolt, it is known through the finite element method that the vibration behavior of the experimental model is mainly controlled by the first two modes, and the bolt material does not have much influence on the modal frequency. Using two different bolts, it can be observed that the frequencies of the two modes will decrease with the increase of the pre-force loss rate, but there will be no significant jump in them, which is not suitable as a pre-tension reference index; Analyzing the signal by FFT, it can be observed that all three fundamental frequencies will have similar behaviors as dynamics. The frequencies will decrease with the increase of the pre-force loss rate. The only difference is that the pre-force loss increases to a certain extent. The frequency deviation rate of high-strength bolts will suddenly increase when the frequency is lower. The frequency deviation of the high-strength bolts at lower frequencies will occur when the loss rate of the pre-tension is lower. Therefore, the insufficient pre-tension of the bolts can be warned earlier. Taking relevant measures as soon as possible is more suitable as an indicator of bolt pretension.measures as soon as possible is more suitable as an indicator of bolt pretension.

[1] D. E. Adams and C. R. Farrar, "Classifying linear and nonlinear structural damage using frequency domain arx models.," Structural Health Moniting, vol. 1, no. 2, pp. 185 - 201, 2002.
[2] H. Alhazmi and R. Guldiken, "Quantification of bolt tension by surface acoustic waves: an experimentally verified simulation study," in Acoustics, 2019, vol. 1, no. 4: Multidisciplinary Digital Publishing Institute, pp. 794-807.
[3] S. M. Y. Nikravesh and M. Goudarzi, "A Review Paper on Looseness Detection Methods in Bolted Structures," Latin American Journal of Solids and Structures, vol. 14, no. 12, pp. 2153-2176, 2017
[4] K. S. P. Langer, C. Guist, S. Marburg, "Finite element modeling for structural dynamic analysis of bolted joints under uncertainty," Procedia Engineering vol. 199 pp. 954 - 959 2017.
[5] Z. Zhang, M. Liu, Z. Su, and Y. Xiao, "Evaluation of bolt loosening using a hybrid approach based on contact acoustic nonlinearity," in 19th World Conference on Non-Destructive Testing, Munich, 2016.
[6] Z. Zhang, M. Liu, Z. Su, and Y. Xiao, "Continuous monitoring of residual torque of loose bolt in a bolted joint," Procedia Engineering, vol. 188, pp. 278-285, 2017.
[7] 內政部營建署, "鋼構造建築物鋼結構設計技術規範," 2010.
[8] 赵功, 王宝瑞, 于广, 阳红, and 黄新宇, "螺栓预紧力对螺栓结合面特性参数的影响规律研究," 机械强度, vol. 40, no. 2, pp. 392-397, 2018.
[9] 赵彤, 郭俊杰, and 吕玉红, "预紧力与非线性作用的螺栓结合部动力学特性," 清华大学学报 (自然科学版), vol. 59, no. 9, pp. 772-779, 2019.
[10] 張志高, "螺栓結構非線性行為有限元素分析," 逢甲大學機械工程學所學位論文, pp. 1-58, 2010.
[11] 陳佳郁, "鋼樑柱接頭剪力板螺栓接合設計與分析驗證," 成功大學土木工程學系學位論文, pp. 1-80, 2017.
[12] 黃立鑫, "螺栓接合之動態特性分析," 國立屏東科技大學機械工程系碩士班學位論文, pp. 1-105, 2003.
[13] 葉慶宇, "剪力板螺栓接合設計與鋼梁柱接頭耐震試驗分析研究," 成功大學土木工程學系學位論文, pp. 1-141, 2019.