Full-size Test Research Articles

Load Distribution Optimization Method for Fatigue Test of Full-scale Structure of Biaxial Resonant Wind Turbine Blade

Wind turbine blade is the key component of wind turbine to realize wind energy capture, so it is necessary to verify the rationality of blade structure design through full-scale structural fatigue test. In order to improve the test accuracy and efficiency, this paper proposes to establish the dynamic analysis model of the multi-degree of freedom system of the tested blade by using the finite beam element to realize the calculation method of the load amplitude of the biaxial fatigue test and integrate the dynamic analysis model and the target load calculation method into the particle swarm optimization algorithm to realize the optimization of the load distribution of the biaxial resonant full-size structure fatigue test. Through the design of a biaxial resonant loading scheme of 2.5MW-52.5m wind turbine blades, the results show that this method can quickly and accurately adjust the optimization parameters such as the position of the exciter and the motion quality of the exciter in the flapwise and edgewise on the premise that the fatigue cumulative damage caused by the test load is not less than the cumulative damage of the target load.

Experimental investigation of spooling test on the multilayer oceanographic winch with high-performance synthetic fibre rope

Compared with steel wire ropes, synthetic fibre ropes have a better performance in deep sea and gradually replaced the former in subsea launch and recovery systems. However, serious damage will be introduced to the winch structure when synthetic fibre ropes wound in multiple layers on the winch drum. In order to comprehensively explore the relationship between the mechanical properties of the winch drum barrel and the synthetic fibre rope, biaxial strain gauges and laser profile scanners have been used to monitor the oceanographic winch using a high-modulus polyethylene (HMPE) rope with the length of 13000 m. The full-size test rig was first introduced as an attempt to quantify the effect of winding fibre rope and evaluate the stresses on the winch with multilayer winding fibre rope. The results reveal that a loss elimination effect on rope windings may occur during the spooling experiment of fibre rope owing to the hysteresis property of the fibre, which differs significantly from the results published previously. Moreover, a more concise winding model is developed to estimate the spoolingand deformation states of the synthetic fibre rope, which can well simulate the cross-section deformation of the wound HMPE rope.

Hybrid heat-pump-driven liquid-desiccant system: Experimental performance analysis for residential air-conditioning applications

A compact heat-pump-driven liquid-desiccant air-conditioning unit for residential buildings is proposed and constructed to validate its energy and air-conditioning performance experimentally. By composing the system with one set of providing the decoupled control of annual sensible and latent loads, the proposed system would contribute to the residential applicability as a packaged multi-functional air-conditioning system. The proposed system consists of a liquid-desiccant dehumidifier to accommodate the latent load and a heat-pump to meet the sensible load of the conditioned zone. The heat-pump also simultaneously accommodates the desiccant-solution cooling and heating demands required in the operation of the liquid-desiccant system. The operating and energy performances of the proposed system for representative summer and winter modes are monitored through a full-size test mock-up in a laboratory. The measurement data reveals that the proposed system can consistently maintain the target supply-air temperature and humidity in each operation mode. In terms of energy efficiencies, the proposed system exhibits an energy efficiency ratio of 7.72 for the summer and a coefficient of performance of 2.51 for the winter operating conditions, which satisfy the approved minimum efficiency requirements. In conclusion, the proposed system has a great application potential for residences in terms of operating and energy performances.

Full size testing and detailed micro-modeling of the in-plane behavior of FRCM–reinforced masonry

Fiber Reinforced Cementitiuos Mortars (FRCM) are a relatively new class of reinforcement used in conservation engineering. However, the structural response of shear walls reinforced with non-isotropic composite material nets, bonded with relatively low-strength and non-elastic mortar matrices is difficult to study with numerical models. The reliability of numerical models could be improved if experimental data was available from full size testing. However, such data is expensive to obtain as large specimens are needed. In this paper, an experimental campaign was carried out at the laboratory on 12 full size wall panels. These were tested in diagonal tension to assess their shear behavior in unreinforced and FRCM-reinforced configurations. Some manipulation of the data is required in order to interpret the experimental results, but diagonal tension testing has many advantages over other testing methods to study the shear behavior of masonry walls. In general the results have demonstrated that FRCM strengthening of shear walls is an effective retrofitting method. Different reinforcement schemes (single- and double-sided retrofits) and bonding inorganic matrices have been studied. Lastly, a two-step non-linear numerical procedure, calibrated with characterization test data and benchmarked on the laboratory outcomes (i.e. full scale testing), has been also implemented to define an effective tool for predicting the shear behavior of reinforced walls.

Seismic Strengthening Effects of Full-Size Reinforced Concrete Frame Retrofitted with Novel Concrete-Filled Tube Modular Frame by Pseudo-Dynamic Testing

The present study proposes a new seismic retrofitting method using a concrete-filled tube modular frame (CFT-MF) system, a novel technique to overcome and improve the limitations of existing seismic strengthening methods. This CFT-MF seismic retrofitting method makes the most of the advantages of both concrete and steel pipes, thereby significantly improving constructability and increasing integration between the existing structure and the reinforcement joints. This method falls into the category of typical seismic retrofitting methods that focus on increasing strength, in which the required amount of seismic reinforcement can be easily estimated. Therefore, the method provides an easy solution to improving the strength of existing reinforced concrete (RC) structures with non-seismic details that are prone to shear failure. In the present study, a full-size two-story test frame modeled from existing domestic RC structures with non-seismic details was subjected to pseudo-dynamic testing. As a result, the effect of the CFT-MF system, when applied to existing RC structures, was examined and verified, especially as to its seismic retrofitting performance, i.e., restoring force characteristics, stiffness reinforcement, and seismic response control. In addition, based on the pseudo-dynamic testing results, a restoring force characteristics model was proposed to implement non-linear dynamic analysis of a structure retrofitted with the CFT-MF system (i.e., the test frame). Finally, based on the proposed restoring force characteristics, non-linear dynamic analysis was conducted, and the results were compared with those obtained by the pseudo-dynamic tests. The results showed that the RC frame (building) with no retrofitting measures applied underwent shear failure at a seismic intensity of 200 cm/s2, the threshold applied in seismic design in Korea. In contrast, in the frame (building) retrofitted with the CFT-MF system, only minor earthquake damage was observed, and even when the maximum seismic intensity (300 cm/s2) that may occur in Korean was applied, small-scale damage was observed. These results confirmed the validity of the seismic retrofitting method based on the CFT-MF system developed in the present study. The non-linear dynamic analysis and the pseudo-dynamic test showed similar results, with an average deviation of 10% or less in seismic response load and displacement.

Corrosion Risk and Repassivation of Duplex Stainless Steel UNS S82551 in Treated Seawater Injection Service

In seawater injection wells, the available well tubing materials are generally low alloy steel, glass-reinforced epoxy-lined low alloy steel or corrosion-resistant alloys such as super duplex stainless steel. However, in treated seawater the corrosion risk can be controlled and lower-grade alloys (low alloy steel) can be considered. But for long well lifetime designs (20 y plus), then low alloy steel tubing can be challenged. In this respect, recent efforts have focused attention on better dissolved oxygen control which permits the investigation and on the possible use of more cost-effective materials such as the duplex stainless steels UNS S82551 and UNS S82541 (the latter is a higher strength version, but same PRENw). Full-scale testing of tubes joined together with a proprietary premium threaded connection (pipe-coupling premium connection [PCPC] couplings) was performed in controlled seawater loops simulating service conditions at 30°C. The flow rate and dissolved oxygen were controlled at 5 m/s and <20 ppb, respectively. Weekly dissolved oxygen excursions corresponding to 24 h at 100 ppb followed by 1 h at 300 ppb were performed during the 5 months exposure. Corrosion results of UNS S82551/S82541 tubing were compared to UNS S31803 and UNS S39274. In parallel, laboratory exposures of creviced coupons for parametric study were performed in dissolved oxygen-controlled cells, allowing the measurement of electrochemical potentials as function of dissolved oxygen content and the related corrosion resistance. The results showed that dissolved oxygen content should be properly controlled below critical values to avoid crevice corrosion of the lesser alloyed duplex stainless steels. The ability of UNS S82551/S82541 to recover or repassivate after prolonged exposures to high dissolved oxygen concentrations (DOC) was also determined with both the use of full-sized PCPC test cells and electrochemical testing involving a remote crevice assembly. The repassivation potential was investigated after different active crevice corrosion durations. The results of the study allowed to precisely define the limits of use of UNS S82551/S82541 in treated seawater, i.e., the critical DOC conditions for corrosion initiation and for repassivation of UNS S82551/S82541. For all tested conditions, the UNS S82551/S82541 showed a rather good ability to repassivation when normal service conditions (i.e., low dissolved oxygen) are recovered.

Methods to Test the Compressive Strength of Earth Blocks

The efficient design of new earth structures and the restoration of old structures both require a reliable assessment of the compressive strength of earth materials. However, there is still much debate on the best method to accurately measure the compressive strength of earth blocks. To solve the problem of measuring the compressive strength of the earth block, the cube specimen, the half‐block stacked specimen, and the full‐size block specimen are used to measure the compressive strength of the molded adobe and rammed adobe, respectively, considering the influence of the specimen preparation process, loading direction, capping, and other factors. By comparing and analyzing the stress state, failure mode, and compressive strength of the specimen under various test methods, a compressive strength test method of earth blocks is determined, which is simple to operate, easy to standardize, and as close as possible to the actual strength of the blocks. The results show that the full‐size block compression test method along the block thickness direction should be preferred to test the compressive strength of the earth block. The standard specimen obtained by cutting the full‐size block is not suitable for the test of the compressive strength of the earth block; it can effectively solve the problem that the compressive strength of the small‐thickness earth block cannot be directly measured by cutting the full‐size block in half and stacking it, but it is not recommended to use the binder to bond the two half‐blocks. When comparing the compressive strength of the earth blocks, the conversion coefficient related to the height‐to‐thickness ratio of the specimen cannot be used to convert the compressive strength. Still, the anisotropy of the material strength should be considered.

Failure analysis of casing dropping in shale oil well during large scale volume fracturing

Shale oil and gas are regarded as typical unconventional reservoir, their recovery often impedes by casing damage. Failure analysis is performed for casing dropping in shale oil well via optical microscope (OM), scanning electron microscope (SEM), full size test and finite element modeling. Morphology observation reveals that thread remains intact under as-received condition after make up and break out. Meanwhile, galling and improper make-up position occur for slipping thread. Full size test exhibits that strength of connection declines from 783.4Kips to 697.1Kips after 9th stage fracturing, with loss of 11.0%. Finite element modeling demonstrates that contact stress reaches to high values at two ends and low values at middle part in the pin and box threads under complex stress. Casing dropping can be attributed to insufficient strength of connection due to improper make-up position, which accelerates by fracturing operation. Finally, dynamic damage effect is suggested to introduce in design of casing string in shale oil well.

РОЗВИТОК НОВИХ КОНСТРУКТИВНО-ТЕХНОЛОГІЧНИХ РІШЕНЬ КРИЛ ЛІТАКІВ І РЕМОНТ КОМПОЗИТНИХ КОНСТРУКЦІЙ

It is shown that in the complex problem of the permanent increase in the efficiency of using polymer composite materials in the construction of aircraft in the transport category, an important role is played by the rational choice of structural and technological solutions of their units and assemblies, which significantly contribute to the implementation of high flight-technological and economic characteristics of aircraft competitive on global market for sales and services. A review and analysis of the development of new wing composite structures discussed at the annual international exhibition Sampe 2019 under the NEWS project, formed in accordance with the STELIA Aerospace R&T strategy for the development of composite technologies with high technical and economic potential, is carried out. A detailed description of the experimental integral demonstrator of the wing compartment molded by infusion is given. The advantages of the selected integrated infusion technology are discussed, including minimizing the assembly steps, process automation, an economical autoclave-free molding process and repair of composite structures. The information provided by Airbus representatives on the repair of composite structures during the operation of the aircraft using portable equipment providing a high-quality curing regime for carbon fiber reinforced plastic. The types of structural repair are described. It is noted that structural repairs can be carried out by means of glue or bolt-on linings certified in accordance with EASA / FAA. The basic requirements of CS25.603 §8.8 are confirmation by analysis and / or test that repair methods and techniques will restore the structure to airworthiness. The justification for the repair is carried out by analysis confirmed by tests. Repairs must meet the same requirements as the original composite structure. Representative damage dimensions are performed in a full-scale test (maximum allowable damage size). A full-size test piece is also included in the evidence base. Repairing composite parts requires a clean environment, for which humidity, dust and temperature control are critical. Therefore, various portable portable “clean room” designs developed by various companies specifically for the repair of aircraft structures were presented at the exhibition.

An Intelligent Coupling 3-Grade Fuzzy Comprehensive Evaluation Approach With AHP for Selection of Levitation Controller of Maglev Trains

During recent years, maglev transportation has made great progress, and as a result, many intelligent levitation control algorithms have emerged. However, enterprises often find it difficult to make a choice when faced with the selection of a controller. The main reason is that the performance evaluation of control algorithms is a complex, multiple-criteria, multifactor coupling problem that cannot be represented by a precise mathematic model. In this paper, a novel artificial intelligent evaluation method for the selection of a levitation controller is developed based on a 3-grade fuzzy method and analytic hierarchy process (AHP). Three kinds of intelligent levitation control algorithms are applied to a full-size test maglev train to collect experimental results with real data. The proposed artificial intelligence method to develop a 3-grade fuzzy multicriteria approach is used to select the best levitation controller for the maglev train. This method can then provide information consultation services to maglev train firms. To the best of our knowledge, for maglev trains, this is the first intelligent evaluation approach with real experimental data. The proposed method can also be applied to other information consultation and decision making systems with appropriate modifications.

A Critical Review of Schmertmann’s Strain Influence Factor Method for Immediate Settlement Analysis

This paper offers an in-depth review of Schmertmann’s strain influence factor method for immediate settlement analysis. The method in question is among the most popular worldwide, whilst, it is included in various important design codes worldwide (e.g. Eurocode 7, FHWA NHI-06-089). As shown, Schmertmann’s method has been proposed without proper and adequate documentation, whilst it presents serious weaknesses related to its calibration and the values adopted for various factors used. In addition, comparison between measured and calculated settlement values of structures or full-size test footings (data taken from independent studies) indicates that Schmertmann’s method is a poor prediction tool. In this respect, an integrated index is suggested for the quantification of the “effectiveness” of the various settlement analysis methods (including the Schmertmann’s one). This consists of the mean and the coefficient of variation of the calculated over the measured settlement ratio values and the percentage of the cases for which the calculated settlement results greater than or equal to the measured settlement. The very low “effectiveness” index values obtained gave rise to investigating the possible sources of error. A parametric finite element analysis was, finally, carried out for supporting the main findings.

Repeatability of Colour Matching Tests using Psychophysical Methods.

The researcher working in the field of illumination can use a number of measurement methods, depending on the requirement. Many practical evaluation methods employ varieties of a configuration where test stations are positioned next to or opposite each other for comparison purposes. Test stations can consist of test booths or even full-sized test rooms when using indoor evaluations. The number of test booths for indoor application may differ from one to three. Most colour and light perception studies thus depend on human observers to provide some feedback or input. It is the human observer who uses illumination devices and it is important that human response to these products be measured. Results achieved from these measurements can, in turn, be used by the lighting designer to optimize the design of illumination products. Many studies in the field of colour perception and/or matching rely on the method of “psychophysics” where humans are used. Reliability of results achieved when using human observers can be questioned. Results achieved with psychometric testing cannot be compared with an established benchmark and/or standard as such a benchmark was itself generated using human observers, endangering the researchers to become entangled in a closed circle of cause and effect where one depends on the other. This study investigated the reliability of human observers when studying colour perception. Repeatability of results achieved when using human observers was measured. A test was repeated using the same set of observers. Even this approach is not safe as human memory may serve the observer so well, that results can be selected, or at least influenced, on the basis of memory and not perception. The solution was to implement extended time between measurements, thereby hoping that sufficient time will lapse to erase details from the observer’s memory. A colour matching task had to be completed to test observers of two distinct age groups. One group was older than 50 years of age and the second group was younger than 40 years of age. The two groups were tasked to complete the same colour matching test at the beginning of a year and after one year. Test procedures and test equipment were identical before and after the year.

Settlement analysis using a generic ballasted track simulation package

Uneven track settlement inevitably occurs for ballasted track and eventually results in poor track geometry and support stiffness leading to considerably high maintenance cost. Considerable in situ and laboratory experiments have been carried out and empirical formulas have been proposed in order to predict track settlement. Nevertheless, laboratory tests are usually restricted in size for financial reasons and the site characteristics vary significantly to fully understand influential parameters. Therefore, the main aim of the present work is to develop an efficient model capable of replicating localised track settlement for different circumstances. A generic ballasted track simulation package BaTrack is introduced combining the Finite Element (FE) software Abaqus, Python, and Fortran. The three-dimensional (3D) FE model includes rail, sleepers, rail-pads, under sleeper pads (USPs), ballast and foundation layers. An advanced non-linear ballast material model is introduced using porous material properties and extended Drucker-Prager model with hardening and is able to account for different confining pressure values. The model is firstly used for comparison against a series of monotonic triaxial tests and has shown good agreement. It is then validated against a series of full size tests carried out at the Southampton Railway Testing Facility (SRTF). A number of settlement analyses are carried out and characteristics of the stress, contact pressure distribution and void evolution from different track configurations are discussed in detail.

Effect of Type B Steel Sleeve Rehabilitate Girth Weld Defect on the Microstructure and Property of X80 Pipeline

In recent years, accident caused by girth weld defects is relatively common. The failure mode of girth weld is mostly fracture. It is an effective way to avoid the failure accident of girth weld to find the hidden trouble of girth weld and repair it in time before the failure. The type B steel sleeve is an effective method to repair the girth weld defects. However, quite few works have been carried out on the reliability verification and engineering practice of repairing the X80 pipeline girth welds. Therefore, it is necessary to carry out full-size physical test for engineering and obtain the influence law of welding operation on main pipeline performance, with the aim of reliability of repair quality and service after repair. In the present work, the reliability study of repairing with type B steel sleeve on X80 pipe girth weld defects was verified. The results show that the bearing capacity of the type B sleeve can effectively guarantee the safe operation of the pipeline in the case of leakage from the girth weld. But there are obvious influence on the material properties of the outer surface of the main pipe due to the welding heat. Effects from longitudinal weld seam is smaller than effects from fillet weld. Grain roughening occurred in heat affected zone of fillet weld which results in that the hardness of the main pipe under the fillet weld increased and the yield strength was reduced by 5.5%. Surface cracking occurs during bending test. There is a certain service risk and it should be used under more frequent monitoring than usual.

On the approximate Riemann solver for the two-phase two-fluid six equation model and application to real system

Abstract A new method is proposed to solve the two-phase two-fluid six-equation model. A Roe-type numerical flux is formulated based on a very structured Jacobian matrix. The Jacobian matrix with arbitrary equation of state is formulated and simplified with the help of a few auxiliary variables, e.g. isentropic speed of sound. Because the Jacobian matrix is very structured, the eigenvalue and eigenvector can be obtained analytically. An explicit Roe-type numerical solver is constructed based on the analytical eigenvalue and eigenvector. A critical feature of the method is that the formulation of the solver does not depend on the form of the equation of state. The proposed method is applicable to realistic two-phase problems. It is applied to the BWR Full-size Fine-mesh Bundle Test (BFBT) benchmark. Considering simplified physical models, the solutions are in very good agreement with those from both existing codes and experiment data. The numerical solver using analytical eigenvalue and eigenvector is shown to be stable and robust.

Investigations into Taylor-Quinney coefficient determination for a 7000 series aluminium alloy using a novel small specimen test technique

Thermo-mechanical coupling is a critical component in the thermodynamics of irreversible processes and is related to the dissipation of thermal energy during plastic straining. The Taylor-Quinney coefficient may be thought of as a ratio between thermally dissipated energy and plastic work, thereby giving insight into the thermo-mechanical coupling term. The inclusion of this parameter in a meaningful way is complicated by the various dependencies that the Taylor-Quinney coefficient may be subject to (e.g. loading rate and temperature). Determination of these dependencies is usually achieved through extensive experimentation, wherein temperature variations are monitored (with reference to an unloaded control sample) in a test piece during mechanical loading. There are practical limitations in full size testing methods however, not least relating to the location of full sized control and loaded samples in an environment chamber/furnace while simultaneously maintaining (control sample) temperature uniformity and high resolution temperature measurement (in the loaded sample). The present work details a method based on a novel small specimen testing technique that is currently under development at the University of Nottingham. A small ring of 7175-T7351 aluminum alloy (approximately 10mm in diameter and 2mm in thickness) is loaded between two pins at room temperature, with the local specimen temperature field monitored during monotonic deformation using an infra-red thermal camera. Experimental results are compared for different pin loading rates (namely 0.1mm/s, 1mm/s, and 10mm/s), with particular emphasis placed on localised temperature variations in areas of expected high plasticity. Differences of approximately 0.6°C were observed between 0.1mm/s and 1mm/s tests, with higher temperatures recorded in the latter. Higher temperatures were also noted at small specimen locations associated with localised plasticity. Fundamental thermal material properties are reported for the 7175 alloy in order to facilitate future analysis and heat equation solution efforts (working towards Taylor-Quinney coefficient determination).

Rollover threshold investigation of a heavy-duty vehicle during cornering based on multi-body dynamics

The objective of this article is to investigate the rollover threshold of a heavy-duty vehicle during cornering. Based on the multi-body dynamics theory, a high-fidelity model is established, which takes account of the chassis flexibility, the suspension nonlinear characteristics, the tire handling model, and Ackermann steering strategy. Furthermore, by the inverse fast Fourier transform method, a three-dimensional stochastic road in space domain is employed in the model to improve the accuracy. A full-size heavy-duty vehicle test was carried out to validate the model. Based on the validated model, the rollover stability and rollover threshold of the heavy-duty vehicle during cornering are investigated. Lateral acceleration, yaw rate, roll angle, and vehicle torsional deflection in different cornering conditions are analyzed. The rollover threshold is summarized by the response surface methodology for the safe cornering purpose. The result shows the practical meaning of improving transportation safety of heavy-duty vehicles and also provides useful insights for developing the rollover warning system.

ECONOMIC-MATHEMATICAL MODELING OF FOUNDATION CONSTRUCTION TECHNOLOGY BY THE “WALL IN THE GROUND” METHOD

Introduction . The article is devoted to the development of the economic-mathematical model of the technological process of the trench foundations’ construction, the indicators of which are related to the machine parameters, ground conditions and construction conditions. Materials and methods . As a criterion of optimality, the specific energy intensity of the process, which is included in the system indicators, is chosen. Dependencies are established in the research, which determine the correlation of the economic parameters of the drilling process (the cost of the machine, the wages of workers, the standard cost parameters) and the main parameters of the machines, namely power and speed. Results . As a result of experiments on the full-size test bench and the experimental model of the machine, theoretical dependences are confirmed, namely, the minimum specific energy intensity and the resulted costs, which are determined depending on the speed of penetration and the power used. Discussion and conclusion . The developed technique could be used to optimize parameters and other constructions and road machinery, which are not limited to the purpose of the present research. The technique is based on determining the optimal values of the penetration rate and the amount of consumed power, corresponding to the minimum given costs.

Thermal behavior of a translucent superinsulated latent heat energy storage wall in summertime

This paper investigates the thermal performance of a translucent solar wall providing, concurrently, storage and restitution of heat, super thermal-acoustic insulation and daylighting to the interior environment. The wall is composed of glazing, silica aerogel used as a transparent insulation material (TIM) and glass bricks filled with fatty acid, an eutectic phase change material (PCM). To assess the TIM–PCM wall thermal behavior, experimentations were conducted in-situ in a full-sized test cell located in Sophia Antipolis, southern France. Experimental data shows that the tested wall is more effective in winter and might cause overheating during the summer mainly due to solar gains and un-cycling behavior of PCM which remains in liquid state. To enhance the energy performance of the wall in summertime, a numerical model describing the heat transfer mechanisms occurring in the PCM layer in combination with the other transparent wall layers is developed. Then, the model of the wall is linked to TRNSYS software to assess the thermal performance of the whole building. The numerical model is validated experimentally and a good agreement is shown comparing the simulated values with the measured data for seven consecutive days in summer and winter. The importance of considering the natural convection effect in the liquid PCM is also demonstrated. Moreover, it was shown that shading devices can effectively reduce overheating while natural night ventilation decreases the indoor temperature without affecting the PCM performance since the outdoor temperature is always higher than the phase change temperature. The use of a glass with selective solar reflection properties depending on the season instead of the ordinary glazing is shown also to be very effective way to overcome the overheating problem. Finally, the TIM-PCM wall is tested under different climate conditions and passive solutions are given to ensure thermal comfort in summer season.

Flexural performance of spliced beam connected and reinforced with self-tapping wood screws

Splicing method of bending elements is important for the restoration of ancient timber structures due to the principle of preserving as much as possible the original material. This study investigates the flexural performance of spliced beams connected and reinforced with self-tapping wood screws. An experimental program based on four-point bending test configuration was conducted to examine the strength, stiffness and ductility of spliced beams. The test results showed that the spliced beams’ average ultimate bending capacity reached 59.5% of the size and load duration adjusted specified bending capacity of the intact beam. Their stiffness achieved 64.3% of the specified design value in Canadian Wood Design Manual. The spliced beams experienced head pull-through failure of the self-tapping screws. This failure mode led to ductile behavior different from the typical tension failure mode of the wood fibers in glulam beam. Based on the experimental results, an analytical model that addressed the specific head pull-through failure mode was proposed to predict the flexural capacity of spliced beams. The analytical model was calibrated by the data of the head pull-through resistance test results and verified by full-size tests. Comparisons of the analytical and the test results reveal that the model can adequately predict the moment capacity of the spliced beams with the corresponding specific failure mode.