Chinese Ancient Wooden Research Articles

Simulation Study on Static Characteristics of Qing-style ‘One Bucket Three Liters’ Column-cap Dou-Gong Bracket

The Dou-Gong bracket is a key transition component between the roof and the column in ancient Chinese wooden structures. In this paper, the static structural behavior of Qing-style ‘one bucket three liters’ Column-cap Dou-Gong Bracket (third-class material) full-scale test model was studied by simulation. The simulation of monotonic static loading was carried out in the vertical (Z-axis) direction, and the simulation of quasi-static loading under horizontal low-cycle reciprocating load was carried out in the horizontal direction (Y-axis, X-axis). The material of the simulation was P. sylvestris, and the setting of its material parameters referred to the results obtained from the material property tests. An anisotropic constitutive model suitable for the properties of wood materials was selected, and the elastoplasticity of wood in the simulation was defined by the Hill yield rule. The static structural behavior of the component in the Z-axis could be described by the variable stiffness linear elastic mechanical model. The static structural behavior of the component in the Y-axis and X-axis could be described by a multi-linear restoring force model. According to the simulation results, the key mechanical indexes of Dou-Gong bracket component in the Z, Y, and X axes were calculated from three aspects of strength, deformation, and energy.

Identification and analysis of ancient ship wood excavated at Nantong hydraulic site

The Nantong Ancient Ship refers to an ancient Chinese wooden ship of the late Ming Dynasty excavated in Nantong city in December 2022. This paper identifies the wood and discusses its related analysis. Wood samples extracted from the Nantong Ancient Ship were studied from the viewpoints of anatomy, physics, and chemistry. Microscopic identification results concluded that willow and Chinese fir were the main wood species used to make this ship. The content of holocellulose in the ancient wood was only 37.9 to 38.9%, while the content of lignin was 55.2 to 56.4%. The cellulose crystallinity of ancient wood was 39 to 42% lower than that of healthy recent wood. Fourier transform infrared (FTIR) spectra revealed that the deterioration of ancient wood caused cellulose and hemicellulose degradation, but no apparent lignin alteration. The results could provide a basis for drawing up a conservation plan for the Nantong Ancient Ship. They could also provide a reference for the research and conservation of other archaeological shipwrecks in China.

Characteristics of Ancient Shipwreck Wood from Huaguang Jiao No. 1 after Desalination.

Huaguangjiao I refers to the ancient Chinese wooden shipwreck of the South Song Dynasty (1127-1279 AD) discovered in the South China Sea in 1996. From 2008 to 2017, the archaeological waterlogged wood was desalted using deionized water combined with ultrasonic treatment, and desalted using EDTA-2Na, EDTAHO, and NaH2PO4·2H2O solutions. In this paper, the degree of degradation of the modified waterlogged archaeological wood and the moisture and content of the main components were determined. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nanoindentation (NI), and scanning electron microscopy (SEM) were employed to investigate the state of wood degradation after desalination and desulfurization. The results showed that the water content of the wood was as high as 532~1149%, while the basic density was only 0.14~0.18 g/cm3, indicating that the wood had been seriously degraded. The holocellulose content was only 36-40%. Based on the XRD patterns, the degree of cellulose crystallinity in the modified wood was 14.08%. The elastic modulus and hardness of the ancient shipwreck wood after desalination and desulfurization were 1.28-4.31 and 0.10-0.28 GPa, respectively, according to nanoindentation. In addition, the FTIR spectra revealed that the biological deterioration of the modified wood caused cellulose and hemicellulose degradation, but no apparent lignin alteration occurred. The results could provide knowledge for appropriate dewatering, strengthening, and restoration strategies.

Consolidation and Dehydration of Waterlogged Archaeological Wood from Site Huaguangjiao No.1

The Huaguangjiao I is an ancient Chinese wooden shipwreck from the South Song Dynasty (AD 1127–1279) discovered in the South China Sea in 1996. The first phase of its conservation, desalination and desulfurization, was completed in 2016. In this paper, three archaeological wood samples exhibiting different degrees of deterioration from Huaguangjiao No. 1 were consolidated with PEG-4000 and dehydrated via freeze drying and supercritical CO2 drying methods. The dimensional stability, hygroscopicity, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used to evaluate the effects of consolidation and dehydration. The results showed that PEG4000 was an efficient consolidation material that also effectively decreased shrinkage during dehydration. Furthermore, both vacuum-freeze and supercritical CO2 drying were efficient methods for treating waterlogged archaeological wood. After PEG4000 impregnation, the shrinkage percentage of the waterlogged archaeological wood became slightly lower than sound wood. The moisture absorption of the experimental specimens ranged within 3.35%–4.53%, and they comprised 50% sound wood, resulting in a marked improvement in dimensional stability. FTIR spectra indicated that impregnation improved wood dimensional stability by reducing hydrophilic groups. These results show that this method can effectively treat waterlogged wood for preservation purposes.

Construction Forms and Seismic Performance of the Ancient Chinese Buildings Joined by Tenon–Mortise Joints

Zijincheng, also known as the Forbidden City, is the largest and best-preserved ancient palace-type wooden building in China, built without using a single nail. Since it was built in 1420, it has served as a palace where the emperor lives and works. Almost 600 years old, it has gone through two dynasties (i.e., the Ming and Qing dynasties (AD 1368–AD 1912)) and 24 emperors. It has survived more than 200 devastating earthquakes throughout its history, and it is still standing strong. In this paper, the authors introduce the construction technology of the ancient Chinese wooden structure as well as the greatest secret of the well seismic performance of the Forbidden City. The study found that the secret to the Forbidden City’s ability to withstand many powerful earthquakes lies in the flexibility of its timber structure, which is mainly reflected in the application of the tenon-mortise joints, energy-dissipation capacity of Dougong brackets and shallow-buried columns. The seismic responses of a 1:5 reduced-scale model of Shoukang Palace of the Forbidden City under different earthquake magnitudes are studied through a series of shaking table tests.

The Influence of Environment on the Settlement of Historic Buildings in China

Chinese ancient wooden buildings prefer fronting water and with hills on the back. Therefore, some ancient buildings were built on the bedrock of the mountain. The uneven height of the building platform from the bedrock causes the uneven settlement of the foundation. Due to the disturbance of groundwater, the uneven settlement of the building foundation will also change due to the groundwater. This paper takes the Song Dynasty Jinci Goddess Mother Hall as an example to compare the settlement of the original foundation and the settlement of the repaired foundation. Summarize the effect of groundwater and the bedrock location of the settlement of ancient building platforms under different strengthening methods. The Flac-3D simulation software was used to simulate the foundation and load of the building. The numerical simulation results show that the settlement value after reparation is reduced by 84% compared with that before. The values of the settlement trend are similar to actual data, which has to guide significance for the prediction of building settlement and the protection of the building. Authors can provide references for future protection and the foundation reinforcement of similar buildings by comparing the foundation reinforcement methods by actual measurement and numerical simulation.

Parametric Design and Aesthetics of 3D Appearance of Ancient Buildings

Ancient architectural design refers to the conservation repair and reconstruction of cultural relics and buildings as well as the design of antique-style architecture. This paper involves using the component-assembly method to perform the architectural design of ancient Chinese wooden buildings by 3D parametric means, including the application of the design method that combines modern industrial serialized group design technology contained in the above means with the trade-off of ancient building modularization. The model can be disassembled and converted into 2D engineering drawings.

Structural analysis of ancient Chinese wooden locks

Humans all around the world have used locks for thousands of years. Wooden locks were the earliest locks in ancient China and were firmly fixed to the door. There are two principal types: bolt locks and pin tumbler locks. The original bolt lock was made with a thick bolt and the door. It could only be opened from the inside of the door. Improved continuously, a large number of wooden locks with different structures were invented. This work presents a systematic analysis of the structures of ancient Chinese wooden locks. The characteristics and the representations of wooden locks are described. There are totally 10 types of wooden locks that are presented as examples to demonstrate the operation processes. According to the insertion position of the key, Chinese wooden locks can be divided into seven types: no entry, bolt entry, case side entry, case bottom entry, case top entry, case front entry, and multiple entries. Ancient Chinese wooden locks come in various types with different ingenious designs, fully demonstrating the work of the highly skilled artisans in ancient Chinese society.

Study on wood preservation state of Chinese ancient shipwreck Huaguangjiao І

Abstract Huaguangjiao І is a Chinese ancient wooden shipwreck of South Song Dyansty (1127–1279 AD). Wood samples from Huaguangjiao І were analyzed in order to evaluate the preservation state of the waterlogged wood. Samples were studied from the anatomical, physical and chemical point of view. Thin slides of cross and longitudinal sections from samples were observed by optical microscope, micromorphological decay was classified into class 3 or class 4 according to the anatomical characters. Water content and basic density were measured. Maximum water content (MWC) of the wood samples is between 300% and 600%, residual basic density is about 50%. The proportion of the α-cellulose decreased to 25% of the normal value, and the content of the ash increased greatly. These results indicate the degradation of the wood is very high. In addition, there is a plenty of inorganic deposit in the wood structure. The inorganic compounds deposited in wood samples were analyzed by XRD and ICP qualitatively and quantitatively. The morphology and composition of the inorganic deposit was characterized through SEM-EDS, the majority were iron sulfide, including pyrite and marcasite (FeS2), and fluorite (CaF2).

Cyclic behavior of Chinese ancient wooden frame with mortise–tenon joints: friction constitutive model and finite element modelling

The beams and columns in Chinese ancient wooden buildings were connected with mortise–tenon joints, which are semi-rigid due to the friction and squeezing deformation between mortise and tenon. In this paper, a friction constitutive model for the friction behavior between mortise and tenon was proposed based on the modern frictional theory. A series of surface topography and hardness tests were conducted to obtain some parameters used in the friction constitutive model. A finite element (FE) model of a Chinese ancient wooden frame with mortise–tenon joints under reversed cyclic loading was performed based on the proposed friction constitutive model, and a FE model using a constant friction coefficient was also carried out. Experimental results were used to validate the results modeled by the two models, and better agreement of the proposed model was observed.

Hysteresis behavior of traditional timber structures by full-scale tests

To study the seismic response of a traditional timber structure in China, a full-scale model capturing the main characteristics of a representative ancient Chinese wooden structure in Song Dynasty (960–1279 AD) was established and tested considering three different levels of vertical loads, which is one-story sophisticated timber structure consisting of four columns and Dou- gong sets. A swing column was used to apply the synchronous horizontal force. Tests under the low-cyclic loading were performed considering three levels of vertical load to reveal the hysteretic behavior of the historic buildings. Based on the observed characteristics from restoring forces, the ancient wooden structure appears to have a good ductility despite of its low inherent energy dissipation capability. Based on the test results, the following relationships are established: loads versus displacements with key turning points, the loads at the key points versus the roof weights, the displacements at the key points with the column diameter, and structural stiffness versus ductility. Finally, a limiting value of drift angle for structural design and the equivalent viscous damping and ductility factor for dynamical response analysis are proposed.

Proteomic identification of organic additives in the mortars of ancient Chinese wooden buildings

A micro-sampling proteomic approach was successfully established to identify flour and blood additives in ancient mortars with high specificity.

Typical Brackets Dimensional Numerical Simulation of the Wooden Structure

Brackets is the ancient Chinese wooden building unique ways and one of the main features of the structure. Its dual function of both structural and architectural: An important component of both the structure itself, because of its flexible features tenon, the dynamic response of the structure can absorb greater energy, play a good role in the earthquake; But it is also a special architectural ornament, can play the effect of beautifying buildings. Therefore, this paper based on the finite element software ABAQUS brackets by the force of the mechanism of failure modes and numerical simulation analysis for the brackets and the whole structure of the wood to provide a scientific assessment and reinforcement.

Aseismic behaviors of ancient Chinese structures strengthened by different methods

To protect Chinese ancient buildings, the aseismic behaviors of ancient Chinese wooden structures strengthened by different methods on the tenon and mortise joints were studied through experiments. Based on actual sizes of an ancient building in the Forbidden City, wooden-frame models with scale of 1:8 of the prototype structure were built, incorporating Yan-wei (dovetail)-type tenon and mortise joints. By manual loading, low cyclic reversed loading tests were carried out to study the aseismic behaviors of the models after their tenon and mortise joints are separately strengthened by an iron hook, carbon fiber-reinforced plastic (CFRP) sheets, and steel components. Nine tests were conducted, including three tests for unstrengthened models and two tests for each of the three strengthening methods mentioned above. Through experimentation, load–displacement hysteretic curves and skeleton curves of the models are obtained. Their energy dissipation capability, stiffness degradation, and deformation performance are studied through analysis. The application range of each method is also discussed. Results show that the wooden models have good deformation performance both before and after the tenon and mortise joints were strengthened. The performance of the strengthening methods depended on the property of interest: CFRP sheets > steel components > iron hook in load bearing capability of the model; iron hook > steel components > CFRP sheets in energy dissipation capability of the model; and CFRP sheets > iron hook > steel components in stiffness degradation of the model. Thus, the engineering application suggestions for different strengthening methods are as follows: iron hooks for small wooden structures, CFRP sheets for medium- and small-sized wooden structures, and steel components for medium- and large-sized wooden structures.

Material Properties Test of Wooden Architecture and its Mechanical Properties

Ancient Chinese architecture is the most representative in Chinese ancient civilization. Now preserved ancient ruins are extremely valuable in historical and cultural value, artistic value and scientific value, so the research on the characteristics of ancient building structures in China and its seismic performance have important realistic significance. On the basis of the existing Chinese ancient wooden buildings, the paper discusses the structure performance of Chinese Ancient Timbering Buildings. According to the existing theoretical knowledge, the paper elaborates the reasons for using the wood of Chinese ancient architecture and analyses the basic characteristics of the ancient wood as building materials. We take the experiment of wooden mechanical property test to study the characteristics of material better, and emphasis narrates the whole process of wood bending strength test, then get the results of wood mechanical characteristics.

Aseismic Constitution Problems and Strengthening Methods of Chinese Ancient Wooden Buildings

Chinese ancient wooden buildings have good aseismic constitutions to survive sorts of natural disasters. However, under earthquakes damages still occur on some of them. To protect Chinese ancient wooden buildings, typical aseismic constitution problems as well as strengthening methods of their members were studied by classification and statistical methods. Based on survey results on large number of Chinese ancient wooden buildings, typical aseismic constitution problems were summed up, causes for the problems were analyzed and the corresponding strengthening methods were proposed. By 2 compared examples, typical strengthening methods were further demonstrated. Results show that typical aseismic constitution problems of Chinese ancient wooden buildings include decay of column root, slack of Tou-Kung, tenon pulled out of mortise, cracks of beam and column and so on; to solve these problems, methods such as replacement, wrap, connection, ensemble and so on are feasible.

The Effect of Driving Method and Crank Arrangements on the Performance of a Reconstructed Ancient Chinese Wooden Horse Carriage

The purpose of this study is to investigate the effect of driving method and crank arrangements on the performance of a reconstructed ancient Chinese wooden horse carriage. The results demonstrate better transmission efficiency when the driving torque of wooden horse carriage acts on the crank shaft. The analysis of crank arrangements shows that the phase angle between front and rear legs on the same side should be 0 deg or 90 deg and the one between the legs on the different sides should be 180 deg. These results are beneficial to the future reconstruction of the ancient Chinese wooden horse carriage.

On the motion of a reconstructed ancient Chinese wooden horse carriage

Lu Ban's wooden horse carriage is the earliest recorded walking machine in ancient China. The purpose here is to investigate the motion of a reconstructed wooden horse carriage. This paper first introduces the structure of the mechanism of ancient Chinese wooden horse carriage. The basic theory behind equation of motion is briefly introduced and the kinematic coefficients of the links and their centers of gravity of the wooden horse carriage are then derived. The non-linear differential equation of motion is then solved by using the fourth-order Runge–Kutta method. Finally, this study investigates the motion characteristics of the horse carriage, including the position, velocity, acceleration, foot trajectory, support leg sequence, and pitch angle. The results can serve as a reference for future optimization and redesign of this ancient Chinese wooden horse carriage and other walking machines.

A Study on the Signature of Ancient Chinese Wooden tablets

A Study on the Signature of Ancient Chinese Wooden tablets

Advances in structural mechanics of Chinese ancient architectures

Chinese ancient architectures are valuable heritage of ancient culture of China. Many historical building have been preserved up to now. The researches on the structural mechanics of ancient architectures show the different aspects of structure and mechanics. Systematical studies on the structural mechanics of ancient architectures have been carried out at Xi’an Jiaotong University since 1982. It is related with the need of repair of some national preservation relics in Xi’an. These studies include: 1) Ancient wooden structures including three national preservation relics Arrow Tower at North City Gate, City Tower at East City Gate, and Baogao Temple in Ningbao, Zhejiang province. 2) Ancient tall masonry building, the Big Goose Pagoda and Small Goose Pagoda in Xi’an. 3) Mechanical characteristics of ancient soil under foundation and city wall; the influence of caves in and under the ancient City Wall on the stability of the wall. 4) The typical Chinese ancient building at the center of city: the Bell Tower and Drum tower. 5) The behavior of Dou-Gong and Joggle joint of Chinese ancient wooden structure. 6) The mechanical behavior of ancient soils under complex stress state. A new systematical strength theory, the unified strength theory, is used to analyze the stability of ancient city wall in Xi’an and foundation of tall pagoda built in Tang dynasty. These researches also concern differential settlements of Arrow Tower and resistance to earthquake of these historical architecture heritages. Some other studies are also introduced. This paper gives a summary of these researches. Preservation and research are nowadays an essential requirement for the famous monuments, buildings, towers and others. Our society is more and more conscious of this necessity, which involves increasing activities of restoration, and then sometimes also of repair, mechanical strengthening and seismic retrofitting. Many historical buildings have in fact problems of structural strength and stability; the need for further studies on structural mechanics and materials is definitely growing.