Nondestructive Testing on Ancient Wooden Components Based on Shapley Value

Abstract

In this study, we propose nondestructive testing methods and combined forecasting models-based stress wave and impedance measurements to obtain accurate internal defects information for wooden building components. Internal defects data for major wooden components of an ancient building in China and reverse laboratory test data on matching tree species indicated various degrees of damage on the pavilion wood structure surface and internal defects in certain pillars. The stress wave method enabled rapid acquisition of two-dimensional plots of test sections; however, the results revealed that the area of stress wave detection was greater than the actual defect area. Moreover, the impedance meter was able to determine the defect position and type in a single path, and the actual defect area was proportional to the absolute error of the drilling resistance. By distributing the errors from the two nondestructive testing methods on the basis of a Shapley value algorithm, we determined the weights of stress wave and impedance meter data in the forecasting models and established combined forecasting models that showed greater accuracy with a mean relative error of less than 6%. This method can improve the prediction accuracy of internal defects in ancient buildings and provide effective data support for practical engineering repair and reinforcement schemes.

Detection and Prediction of Internal Damage in the Ancient Timber Structure Based on Optimal Combined Model

“…Chang et al [24] and An et al [25] found that the result detected by drilling resistance could only reflect the wood damage condition on the probe path; thus, it was difficult to give a specific and intuitive three-dimensional image. In order to obtain more precise information, more drilling resistance paths should be provided [26].…”

“…Although many methods provide nondestructive assessment of the internal damage of old wood in timber structures, no single method can provide a complete data set for analysis [11]. In recent years, many scholars have used a combination of detection methods to detect internal damage of wood components [8,15,20,[24][25][26][27][28][29][30][31]. However, currently, there are not many methods to quantify uniformly the detection results detected by different methods.…”

“…Step 2: based on the idea of variable weight and taking the square sum of error, square sum of logarithmic error, and square sum of reciprocal error as a guideline, three combined forecasting models were established based on the IOWA (induced ordered weighted average) operator [33][34][35], IOWGA (induced ordered weighted geometric average) operator [36,37], and IOWHA (induced ordered weighted harmonic average) operator [38,39]. Additionally, the combined forecasting models based on the entropy value [40,41] and Shapley value [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] were used to compare with the proposed methods.…”

Inspection and evaluation of wood components of ancient buildings in the South-Three Courts of the Forbidden City

“…Shi et al (2009) investigated the Hall of Supreme Harmony and discovered its existing symptoms. According to GB 50005 (2017) standard for design of timber structures, the strength of the elements was verified by arithmetic analysis to meet the requirements, and the parts that needed strengthening were reinforced (Chang et al 2019). Qin et al (2018) selected the wood structure of the well pavilion in the Forbidden City of Beijing, which has the characteristics of ancient architecture of the Ming and Qing dynasties and studied its dynamic characteristics.…”

Effect of column foot tenon on behavior of larch column base joints based on concrete plinth

“…Ancient timber structures are an important component of Chinese culture and Chinese civilization. Ancient timber structures have been used for thousands of years (Chang et al 2019), and they constitute a complete and independent structural system. The timber structures have extremely high research value, and they mostly have been built with wood in ancient Chinese buildings (Li et al 2015).…”