Tensile Tear Research Articles

Seismic performance of CFDST column to steel beam welded-bolted joint with slab

To study the impact of RC slab on the seismic performance of CFDST column to steel beam welded-bolted joint, two CFDST column to steel beam welded-bolted joints with RC slab and two without RC slab were designed and fabricated. Low-cycle reciprocating load tests were conducted to analyze the effects of different configurations and the failure modes, hysteresis curves, skeleton curves, ductility, energy dissipation capacity, beam-end strain of the joint. The results showed that the hysteresis curves of all joints were relatively full and exhibited no pinching phenomenon. All joints experienced ductile failure, with failure modes characterized by tensile fracture at the connection between the steel beam upper flange and the upper ring plate, tensile tearing at the transition sections of the upper ring plate, wavy plastic deformation of the upper flange under compression, or crushing of the RC slab. The RC slab effectively improved the moment capacity, ductility, and energy dissipation capacity of the specimens, and also delayed the stiffness and strength degradation. The moment capacity, ductility, initial stiffness, and energy dissipation capacity of the specimens were reduced by decreasing the number of bolts in the lower ring plate. The nonlinear finite element method (FEM) models of the composite joints were established using Abaqus, and the failure modes and moment capacity obtained from the models were in good agreement with the experimental results. Based on the validated FEM models, some design parameters of the joints were explored.

Damage assessment of fixed U-shaped stiffeners stiffened square plates subjected to close-in explosions

The aim of this study is to suggest an approach for evaluating the damage modes and damage levels of the U-shaped stiffeners stiffened plates exposed to close-in explosions. To achieve this objective, a numerical model was developed in LS-DYNA, and the numerical model was verified by experimental results of the authors. Using this validated model, various U-shaped stiffeners stiffened plates were examined under different blast loads. The study investigated the factors that influence the damage modes of the plates, including the strength and distribution of the blast loads, as well as the geometry of the stiffened plates. The results indicated that the small size stiffened plates exhibited overall damage mode while the large stiffened plate showed localized damage at the same blast load. The blast load distribution on the different size plate led to different damage modes. Additionally, this study found that the slenderness of the stiffened plate had a great influence on the support rotation angle of the tensile tearing threshold. The larger span to thickness ratio can result in larger tensile tearing threshold. Moreover, 400 numerical cases were included and used to classify the damage modes of stiffened steel plates. Based on the damage mechanism of the stiffened steel plate, the damage number (Φ1 and Φ2) which considering the blast loads and material parameters of plate, the maximum incident angle of the blast load(α), and the relative stiffness of the stiffeners and the flat steel plate (κ1 and κ2), and the thickness to span ratio of the stiffened plate (λ) were combined to identify the damage modes of stiffened plates. Furthermore, a flow chart was constructed for determining damage modes based on these considerations. Additionally, a curve surface fitting was performed using Φ1 and λ, the fitting formulas were then used to estimate the deformation characteristics of the stiffened plates with U-shaped stiffeners. The damage levels of the U-shaped stiffeners stiffened plates were then classified as low damage, medium damage, severe damage, and collapse by combining the nominal support rotation angle with the threshold of the global tensile tearing at boundaries. The study result can provide insight into the damage mode identification and damage level classification of stiffened steel plates under explosion. Additionally, this study was a base of damage evaluation of the structure elements (such as steel box girder) include stiffened steel plates under explosions.

Dynamic behaviors of sandwich panels with 3D-printed gradient auxetic cores subjected to blast load

This study experimentally and numerically investigated the blast resistance of sandwich panels composed of steel face sheets and 3D-printed gradient auxetic chiral core. Five gradient strategies were utilized in the design of auxetic core, including uniform gradient, positive gradient, negative gradient, center positive gradient and center negative gradient. Varying blast loadings were applied by adjusting the masses of explosive charges. The deformation/failure modes of sandwich panels were obtained in the experiments, in terms of the face sheets and gradient auxetic core. The effects of impulse and gradient type of auxetic core on dynamic responses of specimens were examined. In addition, the numerical simulation was employed to clarify the deformation process of sandwich panel, and to analyze the deformation mode of auxetic cores under sufficient compression. It was shown that higher impulse was associated with increased plastic deformation in the face sheet and more serious shear and tensile tearing within the auxetic core. The auxetic cores of varying gradient types displayed distinct compress deformation behaviors. Among them, the negative gradient variant exhibited the least permanent deflection, and the superior negative Poisson's ratio effect, indicating enhanced blast resistance. This work not only contributes to a strategy for designing gradient auxetic cores with enhanced blast resistance, but also provides valuable insights into experimentally understanding the response of complex auxetic configurations under blast loads.

Effect of crossing warp architecture on tear strength of 3D orthogonal woven T-shaped reinforcements

T-shaped textile composites reinforced by two-dimensional laminates and simple forms of three-dimensional reinforcements are susceptible to tear failure and delamination at the junction. To address these issues and enhance the tear resistance of composite T-joints, 10 types of crossing warp architecture based on three-dimensional woven orthogonal structures were designed, manufactured and characterized with the aim of optimizing the reinforcement architecture. The assessment of the in-plane mechanical behavior was carried out by a tensile tear load applied to the two flanges of the T-shaped reinforcements. The employment of crossing warp architecture effectively enhanced stiffness, tensile strength, and failure strain. Resistance to the failure of the reinforcement was increased as more crossing warp yarns were employed. To further optimize the crossing warp architecture for reinforcement development, the internal and external crossing arrangements were compared. The new finding was regardless of the crossing warp proportions, the external crossing warp led to a higher resistance to the tear force for the reinforcement than the internal crossing warp. The stiffness and tensile strength of the external crossing warp reinforcements exhibited notable improvement, with a maximum increase of 49.1% and 31.1% respectively, compared with that of the internal warp crossing counterparts. The findings in this research will be useful in manufacturing composite T-joints to tailor the reinforcement architecture with different crossing proportions and arrangements for meeting the required mechanical properties.

Low-velocity impact response of a novel bionic turtle shell back armor sandwich structure

Turtle shell dorsal armor comprises a typical lightweight laminated composite structural material, which is constructed by cuticle and bone layer, with high specific strength and high fracture toughness. The red-eared slider turtle, a widely studied species of turtle, has a rich hierarchical structure. In this paper, according to the structure of red-eared slider turtle shell dorsal armor and the characteristics of each layer as well as by taking into full consideration of the fine structure of cuticle and ventral cortex of the shell dorsal armor, two bionic foam silicone rubber sandwich structures of different levels were prepared. Low-velocity impact test and finite element simulation analysis were carried out to study the mechanical response, specific absorbed energy, and damage mode of the two bionic sandwich structures under different impact energies, hammerhead shapes, and hammerhead radii. By comparing the mechanical response and specific energy absorption with the existing ordinary sandwich structure, we find that the two sandwich structures modeled in this paper exhibit better impact resistance than the ordinary sandwich structure. The shape and radius of the hammer head have a significant effect on the energy absorption characteristics of the sandwich structure, and the damage mode under the hemispherical hammer head is mainly dominated by tensile tearing damage, while the damage mode of extrusion fracture is more obvious under the impact of the conical hammer head. With the increase of the radius of the hammer head, the absorbed energy and specific energy absorption of the sandwich structure increases.

Functionalisation of lignin with urethane linkages and their strengthening effect on PLA composites

Lignin was functionalised by crosslinking with hexamethylene diisocyanate (HDI) through the heterogenous reaction in the solvent dimethyl sulfoxide for preferential improvement in the mechanical properties of composites. The successful synthesis of lignin modified with HDI was confirmed by the instrumental analyses, e.g., FTIR, XPS, and FESEM. The incorporation of optimum crosslinked lignin in polylactic acid (PLA) matrix was systematically evaluated on the basis of their thermal stability, mechanical property, glass transition temperature (Tg), water contact angle, water absorption, and water permeability. The results displayed that incorporation of fillers had prominent effects on tensile tear strength, which could improve tensile strength up to 231 % and elongation at break up to 53 % due to the good interface compatibility between PLA and modified lignin. Further, with the inclusion of fillers, PLA composites exhibited higher crystallinity in comparison to neat PLA.

A novel methodology to characterise the ductile-to-brittle transition behaviour of pipeline steels using the dynamic tensile tear test

Brittle fracture control strategies for high-pressure pipelines are essential to prevent catastrophic failures resulting in significant economic losses and environmental damage. Typically, this is achieved by operating the pipeline well above the ductile-to-brittle transition temperature (DBTT). In general, a series of lab-scale fracture tests, such as the Charpy V-Notch (CVN) or Drop Weight Tear Test (DWTT), are performed at different temperatures to construct the ductile-to-brittle transition curve and determine the DBTT. However, when applied to high-grade steels, correction factors or additional criteria are often necessary to obtain satisfactory results. As an alternative lab-scale testing methodology to characterise high-grade steels, the Dynamic Tensile Tear Test (DT3) has been introduced. Recently, an experimental campaign was conducted with the implementation of a liquid nitrogen spray cooling system to characterise the ductile-to-brittle transition behaviour of X70 grade steel using the DT3 system. In this work, tests were performed at temperatures ranging from −80 °C to 25 °C. The transition behaviour was analysed using measured data, and fractography was performed using Scanning Electron Microscopy (SEM). The DBTT for the considered X70 grade steel was determined, and the performance of the DT3 methodology was compared to CVN and DWTT testing methods. Additionally, numerical models were created using Finite Element (FE) modelling and results were compared to the obtained experimental data. By implementing a stress-strain cleavage criterion in combination with the MBW material model, the models considered both ductile damage and failure, as well as brittle failure and mixed ductile-brittle failure. It can be concluded that the DT3-based transition curve provided a satisfactory DBTT prediction. Furthermore, numerical results showed a good correlation with experimental observations and demonstrated a similar transition behaviour.

Vibration-induced crack tip flipping: A closer look at an unfamiliar phenomenon in pipeline failure analysis

Fracture propagation control is an essential strategy to avoid a catastrophic event involving both economic losses and environmental damage. The Dynamic Tensile Tear Test (DT3) was introduced as an alternative tool to characterise dynamic fracture behaviour of high-strength pipeline steels. Mimicking the in-service loading conditions by imposing a dynamic tensile load, the obtained fracture surfaces closely resemble those observed in full-scale pipeline burst tests. A phenomenon called Crack Tip Flipping (CTF) could also be observed in combination with the formation of Arrowhead Markings (AHMs). The mechanisms provoking these phenomena and their effect on the fracture resistance of the pipeline material have not yet been investigated with respect to pipeline failure. Therefore, a high-speed stereo DIC setup was used to study the fracture behaviour of ×70 grade pipeline steel. The DIC setup identified a mechanical out-of-plane vibration that resulted in an additional torsional loading component. Numerical models were constructed with implementation of the Modified Bai-Wierzbicki (MBW) damage model to validate the experimental observations. Imposing a vibration-induced out-of-plane component resulted in a nearly identical fracture behaviour as observed during experiments. Both the crack path and the final fracture surface could be reproduced. Based on the obtained data, it is suggested that this oscillation causes a rotation of the stress tensor controlled by the through-thickness shear component. As a result, the stress state at the crack front is oriented towards the plane of maximum shear, forming a slanted fracture surface. Notably, the additional torsion load did not affect the load-displacement curve, as the value of the effective stress remains unaffected. Consequently, the fracture resistance, computed from energy values extracted from the load-displacement curve, are not influenced by the occurrence of CTF or the formation of AHMs. Conversely, based on the discussed mechanism of CTF, its presence could indicate the conditions under which pipeline failure occurred.

Mesoscale Simulation of Shaped Charge Jet Forming and Free Flight Based on B-spline and Domain Interpolation Material Point Method

Shaped charge (SC) generates a fluid-like high-speed jet (SCJ) undergoing extremely large ductile stretching without fracture. It is a formidable challenge to accurately track and monitor the mesoscale deformation characteristics of materials using fluid simulation algorithms. To address this issue, the Material Point Method (MPM) is introduced as an efficient particle-based method that discretizes the continuum into Lagrangian particles moving through a fixed Eulerian grid. By possessing all material properties, these particles facilitate tracking throughout the deformation process and enable the implementation of history-dependent constitutive models. Regrettably, the utilization of MPM in the study of SCJ formation is restricted. The objective of this study is to assess the capability of 2D-axisymmetric MPMs in modeling SCJ formation and free flight at the mesoscale, thereby providing valuable guidelines for their application in SCJs. The MPMs employed in this study are based on the B-spline (BSMPM) and domain interpolations (generalized and convected particle domain interpolations in MPM). The numerical results indicate that BSMPM with cubic and quartic splines is the most suitable method for calculating SCJs due to its exceptional continuity and alignment with the experimental data. The mesoscale evolution of particles reveals that the material undergoes impact crushing and tensile tearing, transforming into a low-speed slug and a high-speed jet. The equivalent plastic strain (EPS) in SCJs exhibits a radial expansion from the exterior to the axis in a layered manner. Particles in the outer layer with a thickness of approximately 1/2 exhibit a 'laminar' distribution, while particles near the axis exhibit 'turbulent' distribution and undergo severe deformation. The hierarchical progression of EPS and particle motion traces provides insight into the underlying causes of mesoscale experimental phenomena, such as the axial elongation of voids in the SCJ slug and the radial distribution of the material in three concentric circles.

Influence of thickness on impact resistance of glass fiber woven composite laminates

AbstractTo investigate the influence thickness has on the impact resistance of glass fiber woven composite laminates, a series of impact tests on 1–5 mm‐thick laminates impacted by the hemispherical‐nosed projectile on a one‐stage gas gun are conducted. The influence thickness has on the ballistic limit, energy absorption, failure mode, and damage mechanism of laminates is analyzed. The results show the ballistic limit velocity of 1–5 mm thickness to increase in a linear manner. It is found that the ballistic limit velocity of laminate 5 mm in thickness is 2.8 times greater than that of a laminate that is 1 mm in thickness. As the impact velocity of the projectile increases, the energy absorption of a laminated plate decreases to approximately 10% before becoming stable. Fiber tensile tearing and matrix cracking occurs on the back of the laminate, while the domain failure mode changes from fiber tensile fracture to shear as the velocity of the projectile increases.

Research on the impact resistance of aluminum alloy circular corrugated sandwich plates against different nose shape projectiles

The impact resistance of aluminum alloy circular corrugated sandwich plate is investigated by using the experiments and simulations, and the influence of projectile nose shape and impact velocity on the failure mode and energy dissipation characteristics is analyzed. The experimental results indicate that the projectile nose shape influences the impact resistance of circular corrugated sandwich plates. The ballistic limit velocity (BLV) and energy dissipation of the plate increase as the caliber radius head (CRH) of the projectile increases, and the failure mode gradually changes from shear plugging damage and tensile tearing damage to ductile hole enlargement and petal cracking damage. Numerical simulation results show that the numerical simulation can accurately predict the ballistic limit velocity, failure mode and the impact process.

Deformation behaviors and microstructure evolution of Ti6321 alloy under air blast loadings

The response of the Ti–6Al–3Nb–2Zr–1Mo alloy plate under air blast loading was studied. The deformation of the target plate under explosion increased with the increase of charge. The failure features included inelastic deformation, partial tearing, and tensile tearing under different degrees of loadings. Electron backscatter diffraction (EBSD) and transmission electron microscope (TEM) were used to characterize the evolution of microstructure. The result showed that the density of dislocations has a positive correlation with the blast loadings, meaning the major role of the slip. The twinning would help the slip of dislocations in the deformation. The first type of twins generated under blast loadings were {10–12} extension twins. A high-resolution transmission electron microscope (HRTEM) was employed to study the special boundaries of the {11–24} contraction twins and {11–22} contraction twins. Due to the blast loadings, they were not exactly parallel to the theoretical twinning plane. The twin boundary was parallel to the base plane of the matrix.

Study of dynamic mechanical behavior of 1060-H112 aluminum alloy: Experimental and numerical simulation

1060-H112 aluminum alloy with high ductility is widely used in industrial engineering. The study of its dynamic mechanical behavior has theoretical and engineering application value. In this paper, quasi-static tensile tests from room temperature to 250°C and high strain rate compression tests were conducted using a universal material testing machine and a Hopkinson compression bar. By using a hybrid test-numerical simulation method, a modified Johnson-Cook (MJC) strength model and Cockcroft-Latham (C-L) fracture criterion parameters were calibrated. Subsequently, Taylor impact tests were performed on 1060-H112 aluminum alloy specimens with a diameter of 12.66 mm and a length of 50.64 mm in the range of 176.3–483.03 m/s. Upsetting and tensile tearing were observed in the tests. A 12.68 mm diameter blunt nosed projectile impact test on 2 mm 1060-H112 aluminum alloy plate was also conducted with a light gas gun system, and the speed related parameters and failure modes were obtained. Finally, a three-dimensional model corresponding to the test was established in ABAQUS/Explicit finite element simulation software, and the failure modes of the Taylor rod and the velocity parameters and failure modes of the target impact test were predicted. The results show that the MJC strength model and the C-L fracture criterion can predict the experimental results of the two tests accurately. It shows that the MJC strength model and C-L fracture criterion have high accuracy, and they will play an important role in the application of 1060-H112 aluminum alloy in industrial engineering.

Effects of Different Metals on Properties and Friction and Wear of Composite Materials.

With the vigorous development of the automobile industry, the rubber industry has also made continuous progress. As necessary mixing equipment in the rubber industry, the internal mixer is required to undertake a lot of constant work for a long time, which inevitably causes wear to the internal mixer. On the one hand, the wear of the metal on the end face of the internal mixer will lead to an increase in the gap between the inner mixing chamber and the end face, which will lead to material leakage, affect the material ratio of the rubber mixture, and ultimately affect the performance of the rubber mixture. On the other hand, the wear of the end metal of the internal mixer is an increasing process, and the tiny metal particles of the end metal will be incorporated into the rubber mix along with the mixing process, affecting the performance of the rubber mix. At the same time, the disassembly and repair of the internal mixer are complex, and the end face maintenance is difficult. Therefore, finding a kind of end face metal with good wear resistance, long service life, and no influence on rubber compound performance is essential. This paper takes the end face metal of the internal mixer with severe wear as the research object. The wear degree of the metal after friction between MCYD-4 alloy, YW-15 alloy, wear-resistant stainless steel, tungsten carbide alloy, and the rubber compound is compared. The changes in the properties of the compounds after rubbing were investigated. The study found that the tensile tear properties, wet skid resistance, and rolling resistance of NR/BR composites differed when different end-face metals were selected for mixing, but the gap was small. When the end-face metal is YW-15 alloy, the NR/BR composites have the best dispersibility, the most robust tensile tear performance, the best wet-skid resistance, and minor rolling resistance. When the end face metal is the other three alloys, the physical and mechanical properties of the NR/BR composites are reduced to different extents. In this paper, starting from the actual working conditions, considering both abrasive wear and corrosive wear, the friction and wear between the rubber compound and the four kinds of metals commonly used on the end face of the internal mixer are studied. The metal that has little effect on the performance of the rubber compound and is the most wear-resistant was found. This paper is of great significance for improving production efficiency and prolonging the life of the internal mixer.

Substitution Experiment of Biodegradable Paper Mulching Film and White Plastic Mulching Film in Hexi Oasis Irrigation Area

Biodegradable paper mulch has the advantages of being easily degradable and environmentally benign, but its own performance and adaptability to harsh environments have not been tested. This paper uses scanning electron microscopy and three-dimensional morphometry to microscopically characterize biodegradable paper mulch and white plastic mulch. To analyze and compare their mechanical and hydrophobic properties, and weather resistance, the two mulches were measured through tensile tear load and static contact angle. A comparative analysis of the effect of mulching in the dry crop area of the Hexi Corridor was conducted by comparing the growth index, farm water heat, soil oxygen content, and yield using maize and flax. The test results show that biodegradable paper mulch films were slightly inferior to traditional white mulch films in terms of mechanical and hydrophobic properties, with inadequate insulation and moisture retention, but better in terms of aging resistance, soil oxygen content, and crop insulation and water storage capacity in the middle and growth stages. White mulch film had a better yield enhancement effect on maize, while with biodegradable paper mulch film, this was more significant with flax.

A dynamic tensile Tear test methodology to characterise dynamic fracture behaviour of modern High-Grade pipeline steels

Propagating fractures are a considerable risk for high-pressure pipelines transporting natural gas and other resources to various industries. To ensure structural integrity over several decades, the pipe material is subjected to an extensive fracture analysis. Determination of the fracture resistance is a crucial part in safe pipeline design. In this study, a Dynamic Tensile Tear Test (DT3) is investigated in order to address the issues related to the Charpy V-Notch (CVN) and the Drop Weight Tear Test (DWTT). In contrast to current lab-scale tests, the DT3 method applies a dynamic tensile load instead of an impact to fracture a specimen. Consequently, the DT3 test resembles the actual loading conditions of in-service pipelines. Experiments were conducted at room temperature using high-speed camera imaging. An analysis was made of the dynamic crack propagation in a X70 grade pipeline steel. A long fracture ligament of 172 mm allowed to capture a large steady-state crack propagation section of approximately 135 mm. Both phenomena of crack tip flipping (CTF) and the formation of arrowhead markings (AHMs) were observed on the fracture surface. Scanning Electron Microscope (SEM) images revealed a complex ductile–brittle fracture morphology. The experiments were complemented by a numerical analysis using finite element modelling. Ductile crack propagation was simulated using the Modified Bai-Wierzbicki (MBW) damage model. A good correlation between the numerical predictions and experimental data was obtained.

Experimental study of basalt fiber/steel hybrid laminates under low-velocity impact

Due to their excellent impact resistance, fibre-metal laminates are widely utilised in modern engineering industries such as the construction of aircraft, vehicles and ships. In this study, the low-velocity impact characteristics of basalt fibre/steel hybrid laminates with different lay-up structures were studied with a drop hammer. This was done through a series of low-velocity impact experiments with different hammer head shapes and impact energies. It can be seen from the results that the impact behaviour of hybrid laminates largely depends on the shape of the hammer head, impact energy and lay-up structure. The sharper the hammer head, the smaller the peak impact load and the greater the displacement. When the hammer head penetrates the laminate, apparent shear failure occurs under the impact of the flat hammer head. Petal-like fractures caused by tensile tear failure occur under the impact of the hemispherical and conical hammer head. Low-energy impacts may result in large plastic deformation, delamination and debonding in the layers. High-energy impacts may also lead to fibre and metal fractures as well as perforation damage. Consequently, the laminate absorbs the energy from overall deformation under low-energy impact, but mainly absorbs the energy generated by various fibre and metal fractures under high-energy impact.

Influence of U-shaped stiffeners on the blast-resistance performance of steel plates

U-shaped stiffeners stiffened plates subjected to blast loads were investigated in the study. Field blast experiments were performed, and a fine finite element (FE) model was constructed and validated by the experimental results. Four damage modes of the stiffened plates were discovered by parametric analysis: (I) large plastic deformation, (II) partial steel plate damage or stiffener rupture, (III) tensile tearing at the boundary, and (IV) shear failure. In this study, the influence of U-shaped stiffeners on the blast-resistance performance of steel plates was investigated. The damage modes, energy absorption, and deflection responses of the stiffened plates were investigated to understand the influence of U-shaped stiffeners. The damage modes could be changed by the stiffeners, and were significantly related to stiffener characteristics. When stiffeners of the same thickness were used, the ratio of energy absorption of the steel plate to stiffeners (QSP/QST) decreased as the number and size of stiffeners increased. However, when the same equivalent thickness plates were adopted, the QSP/QST may be remained stable while a sufficient number and size of stiffeners were used. The average residual displacement (Daverage) and nominal support rotation angle (α) decreased linearly with the number and size of stiffeners, and increased when the same thickness stiffeners were used. While plates of the same equivalent thickness were used, the stiffeners could sometimes effectively decrease the Daverage and α of the stiffened plates. However, when large deformation occurred, the Daverage and α of the stiffened plates were comparable to those of bare steel plates with the same equivalent thickness.

Research on the Response Characteristics of Bio-Inspired Composite Sandwich Structure under Low Velocity Impact

In order to research the impact mechanical response characteristics of the bio-inspired composite sandwich structure, the hemispherical impactor is preloaded with different energy to impact bio-inspired and conventional composite sandwich structure, the stress distribution and dynamic response characteristics of composite sandwich structure under impact load are studied. The results show that the main damage of the upper panel is fiber shear fracture, while crushing fracture for the core, and the main damage of the lower panel is fiber tensile tearing under different impact load. The bio-inspired composite sandwich structure shows better impact resistance in terms of damage depth and maximum impact load under the same impact energy. From the perspective of energy consumption, the bio-inspired structure absorbed more energy than conventional structure under high energy impact.

Preparation and Application of Polyurethane Coating Material Based on Epoxycyclohexane-Tetrahydrofuran in Paper Conservation

Paper cultural heritages are valuable historical records and also abound in cultural resources. Due to its organic property, paper is susceptible to aging, destruction by environmental pollution and human factors. At present, many countries in the world are facing the problem of paper conservation. Coating reinforcement is one of the methods for paper conservation, in which the choice of reinforcing resin is key. A transparent polyurethane, based on epoxycyclohexane (CHO)-tetrahydrofuran (THF) copolyether, was adopted in this study. The ring-opening polymerization for generating the CHO-THF copolyether took place by the reactants CHO and THF, in the catalysis of boron trifluoride diethyl etherate, initiation of glycerol. Characterizations of the synthetic copolyether were conducted by infrared (IR) spectroscopy and proton nuclear magnetic resonance (1HNMR) spectroscopy. The transparent polyurethane was then produced by the CHO-THF copolyether and hexamethylene diisocyanate (HDI) trimer. The influences of different concentrations of polyurethane solution upon the paper tensile strength, elongation, folding endurance, tearing strength, gloss, and brightness were studied. These findings suggest that 10% polyurethane solution is optimal, not only for greatly improving the paper performance, but also for keeping with the principle of “repair as old”. The applied results demonstrate that the polyurethane based on the CHO-THF copolyether has the characteristics of copolyether along with polyurethane, displaying good mechanical properties in paper reinforcement.