Table of Content

28 August 2025, Volume 0 Issue 8

Previous Issue    Next Issue

BASIC AND MECHANICAL PERFORMANCE RESEARCH

High strain rate impact behaviour of epoxy resins at different temperatures

ZOU Kai, LIU Zheng, ZHAO Changfang, LIU Hao, LIU Chen, ZHANG Kebin

2025, 0(8):  1-7.  DOI: 10.19936/j.cnki.2096-8000.20250828.001

Asbtract ( 107 )   PDF (4900KB) ( 329 )  

References | Related Articles | Metrics

In order to study the dynamic compressive mechanical properties of epoxy resin under high strain rate loading and different temperatures, the yield stress of epoxy resin with strain rate of 0.001 s^-1 was obtained through quasi-static test, and then the dynamic compression test of epoxy resin was conducted by SHPB method. The stress-strain curves under uniaxial compression at temperatures of 25 ℃, 50 ℃ and 70 ℃ and strain rate of 1 000 s^-1, 2 500 s^-1, 3 000 s^-1 were obtained, and the dynamic constitutive relations including strain rate effect and temperature effect of epoxy resin at high strain rate were obtained. The results show that the epoxy resin has strain rate effect, and the development trend of the stress-strain curves of the three high strain rates is the same. Finally, the relationship between yield stress, temperature and strain rate was fitted to describe the relationship between yield stress and temperature of epoxy resin at high strain rate. Based on this, the established constitutive model considering the influence of strain rate and temperature can well describe the stress-strain relationship of epoxy resin at high strain rate, and the research results can provide references for the study of constitutive model of epoxy resin.

Time-domain constitutive modeling of viscoelastic composites based on asymptotic homogenization method

WU Shunxin, ZHU Shuiwen

2025, 0(8):  8-14.  DOI: 10.19936/j.cnki.2096-8000.20250828.002

Asbtract ( 50 )   PDF (5361KB) ( 356 )  

References | Related Articles | Metrics

The aim of this paper is to establish an efficient and accurate method for modeling the macroscopic constitutive relationship of viscoelastic composites. By combining the asymptotic homogenization theory and the eigen-displacement method, a quantitative relationship between the microstructure and the macroscopic response is established. The reduced-order homogenization method is used to solve the characteristic displacement, which effectively improves the computational efficiency and directly obtains the macroscopic ontological relationship in the time domain. The obtained ontological relationship is embedded into the finite element software ABAQUS in the form of a user-defined material subroutine (UMAT), and the reliability of the model is verified by comparison with Digimat. The numerical results show that the fiber volume fraction and viscoelastic decay ratio have a significant effect on the stress relaxation behavior of the composites. As the fiber volume fraction increases, both the initial stress value and the stress relaxation rate of the composites increase; while the increase in the decay ratio leads to a slower stress relaxation rate. It is shown that the method can accurately predict the time-domain mechanical response of viscoelastic composites, which provides a strong theoretical support for the design and optimization of composites.

Study on the influence of PVDF electrospun nanofiber membranes with different areal densities on the interlaminar fracture toughness of CF/EP composite laminates

PENG Yan, WEI Liaoxian, ZENG Tangyu, MA Chuanguo

2025, 0(8):  15-23.  DOI: 10.19936/j.cnki.2096-8000.20250828.003

Asbtract ( 33 )   PDF (9973KB) ( 328 )  

References | Related Articles | Metrics

This study examines the reinforcing impact of polyvinylidene fluoride (PVDF) nanofibrous membranes when used as an additive material on the interlaminar fracture toughness of carbon fiber/epoxy (CF/EP) composite laminates with different areal densities. Here, PVDF electrospun nanofibrous membranes with three different areal densities (9 g/m², 15 g/m², 28 g/m²) were prepared and inserted into the interlaminar layers of the laminates for experimental analysis. The results show that the PVDF nanofibrous membrane with a 15 g/m² areal density provided the most significant enhancement of the interlaminar fracture toughness of the laminate, with 67% and 13% enhancement of the mode Ⅰ and mode Ⅱ fracture toughness, respectively, with respect to that of the laminate without the introduction of the PVDF nanofibrous membrane. SEM analysis reveals that the toughening mechanism of PVDF nanofibrous membranes mainly included the processes of fibre bridging, pull-out and fracture. Furthermore,based on the numerical simulation of mode Ⅰ and mode Ⅱ interlaminar fracture behaviours using the finite element simulation method with cohesion model, it is found that the incorporation of PVDF nanofibrous membranes did not significantly change the interface strength of the interlaminar region, but effectively prevented the propagation of the interlaminar cracks through the action of the fibrous skeleton. The numerical simulation results were in good agreement with the experimental results, which verifies the feasibility of cohesion model in simulating the interlaminar cracks in PVDF nanofibrous membranes.

Investigation on the energy absorption mechanism and high-efficiency modeling method of carbon fiber reinforced composite structures

WANG Kai, LUO Junjie, YAO Ruyang, PANG Tong, JIA Xiaohang, YU Lei

2025, 0(8):  24-32.  DOI: 10.19936/j.cnki.2096-8000.20250828.004

Asbtract ( 42 )   PDF (11826KB) ( 312 )  

References | Related Articles | Metrics

Failure mechanisms of carbon fiber reinforced polymer (CFRP) are complex, and fine-scale simulations are costly with low optimization design efficiency. To improve the simulation and optimization design efficiency of energy-absorbing components of carbon fiber composite materials, CFRP thin-walled square tubes were prepared and axial compressive crushing tests were conducted. A multi-layered and refined finite element model of the axial crushing of CFRP thin-walled square tubes was established, and the experimental and simulated failure modes and energy-absorption mechanisms were analyzed. A high-fidelity and high-efficiency equivalent modeling method was proposed. The experimental results showed that the energy-absorption mechanism of the progressive crushing failure mode of the CFRP thin-walled square tube is complex, mainly including fiber fracture, delamination, and frictional dissipation. The simulation results showed that the refined finite element model can accurately modelling the progressive crushing failure behavior and energy dissipation of the CFRP thin-walled square tube. Plastic deformation and damage are one of the main factors of energy dissipation. Based on the progressive crushing failure mode, the proposed modeling method can accurately predict the energy absorption response of the CFRP thin-walled square tube. The relatively fine modeling method has increased computational efficiency by 97%.

Study on the thermal-oxidative aging characteristics of aramid Ⅲ paper-based composites

YAO Yunzhen, LIAO Sihuang, ZHANG Zheng, LONG Jin, WANG Yi, XIONG Zhiyuan, HU Jian

2025, 0(8):  33-42.  DOI: 10.19936/j.cnki.2096-8000.20250828.005

Asbtract ( 19 )   PDF (19944KB) ( 269 )  

References | Related Articles | Metrics

In this paper, aramid Ⅲ paper base paper was obtained by wet forming with aramid Ⅲ staple fiber and meta-aramid fibrid, and then the aramid Ⅲ paper base composite was obtained by impregnating polyimide resin, and then the aging experiments were carried out at 250 ℃, 300 ℃ and 350 ℃. The physicochemical structure, mechanical properties and dynamic mechanical properties of Fang Ⅲ paper before and after aging were described. The results show that the chemical structure of aryl Ⅲ paper has no obvious change before and after aging at 250 ℃ and 300 ℃, and the amide bond breaks before and after aging at 350 ℃. For the physical structure of paper, with the increase of aging time and aging temperature, the quality loss and size loss of aromatic Ⅲ paper gradually become larger, and the paper surface defects such as holes and cracks appear. After aging at 250 ℃ for 408 h, the tensile strength and tear strength retention rates of Fang Ⅲ paper were 111% and 115%, respectively. After 312 h aging at 300 ℃, the tensile strength and tear retention rate of aromatic Ⅲ paper decreased to 53% and 23%, respectively. After aging at 350 ℃ for 168 h, the tensile strength retention rate of aromatic Ⅲ paper was only 4%, the tear retention rate decreased to 14% after aging for 48 h, and decreased to 0 after 168 h. DMA shows that the loss factor transition temperature of aromatic Ⅲ paper increases gradually with the increase of aging time at 300 ℃, indicating that the molecular segment softness and viscosity of aromatic Ⅲ paper increase significantly at 300 ℃.

Experimental and numerical simulation of crack propagation evolution of PVDF membrane

LI Wenrui, LIU Ping, YIN Lingfang

2025, 0(8):  43-53.  DOI: 10.19936/j.cnki.2096-8000.20250828.006

Asbtract ( 26 )   PDF (20773KB) ( 274 )  

References | Related Articles | Metrics

The tearing resistance is very important to the safety of the membrane structure. In the present paper, uniaxial tensile test and numerical simulation were carried out to study the tearing behavior of PVDF membrane with initial slit. The numerical model of yarn and matrix microstructure was established using ANSYS LS-DYNA software, and the tearing process of membrane was analyzed under different slit angles and positions. The tearing strength and failure mode characteristics of the film were obtained, and the effects of different slit angles on the tearing properties of the textile were discussed. The results show that according to the different angle of slit, the section shaped like “a straight line” “Z” and “√” can be formed; under tearing test and numerical simulation, the slit expansion process of the film are identical, and the matrix breaks before the yarn. The error of the numerical simulation is less than 10% at different angles, which indicates that the finite element method can predict the tearing strength of the film well.

Tensile properties and damage evolution of a 2.5D braided quartz/phenolic composite at elevated temperatures

JIAO Lei, RUAN Hao, SU Ruiyi, GE Zhifu, LI Mei, ZHANG Chengyu

2025, 0(8):  54-65.  DOI: 10.19936/j.cnki.2096-8000.20250828.007

Asbtract ( 27 )   PDF (12249KB) ( 268 )  

References | Related Articles | Metrics

Quartz/phenolic composite is a kind of thermal protection material widely used in aerospace vehicles. The study of its high temperature tensile properties and damage mechanism is of great value to the application of resin-based thermal protection materials. To this end, this paper tested the tensile properties of a 2.5D braided quartz/phenolic composite (2.5D-SiO_2f/phenolic), and the test temperature range was from room temperature to 800 ℃. Acoustic emission technology is used to dynamically monitor the damage evolution of tensile specimens at room temperature, combined with scanning electron microscope to observe the fracture morphology, and analyze its tensile damage mechanism. The results show that the tensile strength at room temperature can reach 275 MPa and the modulus can reach 17 GPa. In the range of room temperature to 800 ℃, the tensile properties of 2.5D-SiO_2f/phenolic gradually decrease with increasing temperature. It is revealed that during the 2.5D-SiO_2f/phenolic stretching process, there are mainly damage signals in the frequency range of 70~100 kHz, 220~270 kHz, 300~330 kHz, corresponding to the three damage modes of matrix cracking, fiber and matrix debonding, and fiber fracture. In this way, the evolution process of tensile damage is analyzed.

Moisture absorption behavior of epoxy resin cured products and its influence on the dielectric properties

ZHANG Dujuan, LI Yafeng, LI Songming, LU Haijun

2025, 0(8):  66-73.  DOI: 10.19936/j.cnki.2096-8000.20250828.008

Asbtract ( 48 )   PDF (5649KB) ( 294 )  

References | Related Articles | Metrics

To investigate the moisture absorption behavior of epoxy resin and the changes in its dielectric properties post-absorption, the study developed epoxy resins with various structures by varying the type of curing agent. The moisture absorption rate of the cured materials was monitored under 70 ℃ water immersion conditions, and the dielectric properties were tracked. The results indicated that the moisture absorption process followed the Fick diffusion model, the type of curing agent affects the polarity and free volume of the cured material, the polarity determines the equilibrium moisture absorption rate of the resin, and the polarity and free volume jointly determine the diffusion coefficient of water molecules. The greater the polarity, the higher the moisture absorption rate of the resin equilibrium, and the easier it is for the polar groups to form hydrogen bonds with water molecules and hinder the movement of water molecules. The larger the free volume, the more diffusion channels the water molecule has, and the faster the diffusion. The dielectric properties of the cured matter are different with different curing agents, and the dielectric constant and loss tangent change linearly with the moisture absorption rate and are independent of the type of curing agent. Based on this research, a model was developed to predict the dielectric properties of epoxy resins as a function of their moisture absorption rates, with a deviation of no more than 10% between model predictions and actual measurements.

DESIGN AND TECHNIQUE

Interface parameter analysis of laminates with non-ideal defects

XU Dong, HUANG Zhiqiang, CHEN Song, XIE Jingjing

2025, 0(8):  74-85.  DOI: 10.19936/j.cnki.2096-8000.20250828.009

Asbtract ( 19 )   PDF (9792KB) ( 263 )  

References | Related Articles | Metrics

Considering the influence of bridge fibers, a representative volume element(RVE) with damaged regions of vanishing thickness and a spring model with no thickness is established to characterize the ideal and non-ideal degree of cracks by two independent interface parameters(interface parameters can be used to simulate non-ideal degree in the sensitive interval) is developed to study for estimation of lanimates with transverse matrix cracks. For laminates with open and closed cracks, pending partition loads are applied in the statically indeterminate boundary. This paper not only consider three cases of the idela cracks, the smooth plane-surface open crack, the smooth plane-surface closed crack and the perfect meshing open crack, but also two cases of the non-ideal cracks, the open cracks and the closed cracks. The study not only verifies the symmetry of the flexibility element and the equality of the change rate of the shear flexibility element under closed cracks, but also shows that the non-ideal degree of cracks has a great influence on the effective coupling coefficient and the effective shear flexibility.

Curing deformation simulation of foam sandwich composite C-shaped panels

NIE Zhiwei, LUO Qi, HUO Yufan, ZHOU-HE Lezi, ZHOU Huamin

2025, 0(8):  86-96.  DOI: 10.19936/j.cnki.2096-8000.20250828.010

Asbtract ( 23 )   PDF (17988KB) ( 315 )  

References | Related Articles | Metrics

Based on the curing deformation mechanism of sandwich composites, a numerical simulation model of the curing deformation of sandwich composites was established for sandwich composite C-shaped contour panels. The simulation results show that at the beginning of demolding, the inner surface of the C-shaped profile plate is subjected to tensile stress while the outer surface is subjected to compressive stress, and the whole component shrinks inward. Based on this simulation model, the curing deformation law of the C-shaped contour panels under different process conditions, such as the type of material at the gap, the number of layers, and the angle of the layer, was investigated. It is found that the curing deformation is the smallest when the gap was not filled with any material, and the curing deformation was the largest when it is filled with composite material; the deformation is positively correlated with the number of layers within a certain range; the lay-up angle has little effect on the deformation. In addition, a number of C-shaped contour panels with the corresponding process conditions were molded, and the curing deformation of the panels was determined by three-dimensional scanning. The simulation conformed well to the experiment, thus verifying the accuracy of the simulation model and realizing the accurate prediction of the curing deformation of C-shaped contour panels.

Finite element simulation modeling and analysis of the dynamic physical processes involved in curing composite components

SUN Siyuan, YANG Yong

2025, 0(8):  97-103.  DOI: 10.19936/j.cnki.2096-8000.20250828.011

Asbtract ( 37 )   PDF (6321KB) ( 277 )  

References | Related Articles | Metrics

Reinforced composite materials quickly rise to prominence in advanced material applications due to their lightweight nature as well as their exceptional resistance against high temperatures and corrosion. They are currently a focal point in researches related to advanced material science, such as high-speed rail technology and other emerging fields. This study aims to provide a more precise analysis of solidified dynamic physical simulations relating to composite components. In this study, we choose the COMSOL Multiphysics software to conduct comprehensive simulations on the temperature field and the solidification field of a C-beam structure. First, we establish simulation models about the temperature field and the solidification field of the C-beam structure. Second, we analyze the solidification dynamic physical process during the forming process of the composite material pressure vessel, using the numerical analysis of finite element under the preset attributes of the composite material molds and parts when the pressure vessel is formed. Finally, we acquire a deviation not above 2.5% through analyzing the simulation data. Meanwhile, this study proposes new directions on the optimizing the solidification process of composite material parts in pressure vessels through analyzing the temperature curves of the C-beam structure on five feature points.

Prediction of composite material cure deformation and mold surface optimization

CHEN Heng, MA Xiuju, SUN Longgang, MAO Haifeng, ZHOU Xian

2025, 0(8):  104-110.  DOI: 10.19936/j.cnki.2096-8000.20250828.012

Asbtract ( 24 )   PDF (5480KB) ( 302 )  

References | Related Articles | Metrics

This paper establishes a multi-factor numerical model for the curing process of composite materials, exploring the temperature distribution of parts during resin curing using a thermo-chemical coupled heat transfer model. A constitutive model based on instantaneous linear elasticity theory, considering the evolution of material parameters, was used to describe the mechanical behavior of the material during the phase change process, predicting the curing deformation trend of end-rib honeycomb sandwich components. The reliability of the model was validated through experimental results. Based on the simulation analysis results, the tool surface was optimized. A comparative analysis was conducted between the parts prepared using the optimized tooling and the theoretical part surface. After tool optimization, the maximum deformation of the molded part’s surface compared to the theoretical part dimensions was reduced by 86.98%.

ENGINEERING APPLICATION

Research on the friction characteristics and thermal capacity of C/C-SiC composite materials applied to the friction blocks for 600 km/h maglev train

LIU Peng, LI Yang, YUAN Yuqing, LI Pengtao, YUAN Minge, ZHANG Jinyu, ZHENG Yong, XIAO Peng

2025, 0(8):  111-117.  DOI: 10.19936/j.cnki.2096-8000.20250828.013

Asbtract ( 23 )   PDF (8701KB) ( 269 )  

References | Related Articles | Metrics

C/C-SiC composite materials have been used as skid shoes and have operated safely at 430 km/h on the Shanghai High-Speed Maglev Demonstration Line for nearly 20 years. With the advent of 600 km/h high-speed maglev trains, it is urgent to investigate the friction characteristics and thermal capacity analysis of C/C-SiC composite material friction blocks for application in 600 km/h maglev trains. This paper first obtains the friction coefficient and temperature rise characteristics of the C/C-SiC composite material through 600 km/h high-speed friction tests. Under the test conditions of 600 km/h, a Z-direction pressure of 4 kN, and continuous friction for 8 min, the highest temperature recorded by the sensor reached 569.2 ℃ and tended to stabilize, which is far below the material’s allowable temperature limit. The average friction coefficient is below 0.1, meeting the technical requirement of minimizing the friction coefficient in high-speed friction environments. Using a thermal capacity simulation calculation method to replicate the high-speed friction test temperatures, the distribution coefficient of the friction heat flux density between the C/C-SiC composite material and the rail wheel is determined to be 0.020 54. Based on this parameter, the simulation predicts the temperature characteristics of the C/C-SiC composite material when it drags at 600 km/h for 300 km in the event of a suspension failure in the high-speed maglev train, providing support for the design optimization and engineering application of 600 km/h high-speed maglev trains.

Design and experimental study of carbon fiber composite multi-leaf springs for heavy truck suspension

WANG Yi, HU Yefa, WANG Baokun, WU Shuihua, FU Kai, WEN Xianglong, ZHANG Jinguang

2025, 0(8):  118-124.  DOI: 10.19936/j.cnki.2096-8000.20250828.014

Asbtract ( 26 )   PDF (6965KB) ( 293 )  

References | Related Articles | Metrics

This paper introduces carbon fiber reinforced plastic (CFRP) into the design of heavy truck leaf springs and propose a CFRP multi-leaf spring structure. Using finite element simulation analysis to coordinate and match the strength and stiffness of CFRP multi-leaf springs, which yields a lay-up angle of [0₃₃/±75]₅ for the CFRP single leaf spring, and optimize the simulation model by bench test, used ABAQUS software to establish the optimized finite element simulation model and CAE to predict the stiffness and fatigue life of CFRP multi-leaf springs under the conditions of working load, ultimate load and fatigue loading, and carry out reliability analysis of CFRP multi-leaf springs. Reliability analysis is carried out to predict the stiffness and fatigue life of CFRP multi-leaf springs, and bench tests are carried out on CFRP multi-leaf spring test pieces. The results show that the mass of the CFRP multi-leaf spring is 34.4 kg, achieving a weight reduction of over 45%. Additionally, the stiffness of the CFRP multi-leaf spring does not decrease after 150 000 cycles of cyclic loading, and it can still withstand a load of 20 tons without damage.

Structural performance research of wind turbine tower based on BIM+FEA

WANG Ailing, ZHAO Ying, SUN Shaonan, XIAO Ying

2025, 0(8):  125-131.  DOI: 10.19936/j.cnki.2096-8000.20250828.015

Asbtract ( 20 )   PDF (6375KB) ( 262 )  

References | Related Articles | Metrics

Aiming at the structural response of the tower under complex loads and different working conditions, the structural performance of a 2 MW large-scale horizontal-axis wind turbine tower is analyzed by adopting the method of building information modeling(BIM)+finite element analysis(FEA). Firstly, the BIM model of wind turbine is parametrically established and the tower load is analyzed and calculated, then the tower BIM model is converted to finite element model, and finally the tower is simulated and analyzed in finite element software ANSYS. The results show that the maximum stress of the tower occurs at the bottom and the maximum displacement at the top of the tower. The first six orders of the tower’s intrinsic frequency do not resonate with the tower, and the intrinsic frequency of the tower decreases with the increase of the tower height. The intrinsic frequency of the tower decreases with the increase of the top mass of the tower, and the change of the top mass of the tower has less effect on the stress and top displacement of the tower and more effect on the intrinsic frequency of the tower. The research show that the BIM+FEA method can provide new ideas for the structural safety analysis of wind turbine towers, which can provide safety warning in the design and operation and maintenance of wind turbine towers, and provide effective data and information for managers’ decision-making.

Analysis of anti-bird strike performance on GLARE laminate structure

TIAN Xiaoyu, ZHANG Fa, JI Shengcheng, SHI Chen, WU Xiaoguang, LIN Dakai

2025, 0(8):  132-141.  DOI: 10.19936/j.cnki.2096-8000.20250828.016

Asbtract ( 27 )   PDF (9202KB) ( 273 )  

References | Related Articles | Metrics

With the development of aeronautical technologies, the speed of aircraft is improved dramatically. The probability of bird impact on aircraft during take-off and landing is greatly increased. It will result in the aircraft crash. In order to guarantee flight safety, CCAR25 airworthiness regulations have made relevant requirements for impact resistance of the leading-edge structure. Glass fiber reinforced aluminum (GLARE) as a kind of material with good impact resistance, it has been applied to the empennage leading-edge structures such as A380. In this paper, firstly, the methods and theory of anti-bird strike for GLARE leading edge structure is introduced. The analytical method has been verified. Secondly, the finite element analysis method and explicit impact software LS-DYNA is used, the four same thickness but different lay-up of GLARE leading edge structure has been studied. Thirdly, the study is conducted on different curvature GLARE laminate structure. According to analysis the failure mode, the results shows that the deformation and failure of GLARE laminate structure, structure energy absorption, stress nephogram and bird strike force. It is found that the GLARE laminate structure with 3/2[A/+45/-45/+45/-45/A/+45/-45/+45/-45/A] and curvature radius of 100 mm has the best impact resistance.

REVIEW

Advances in the application research of thermoplastic composites in the aerospace field

LIU Daijun, MA Xiaoyi

2025, 0(8):  142-147.  DOI: 10.19936/j.cnki.2096-8000.20250828.017

Asbtract ( 44 )   PDF (3527KB) ( 279 )  

References | Related Articles | Metrics

Thermoplastic composites (TPC) have the characteristics of light weight, high strength and recyclability. They are one of the key materials to achieve the goal of Net Zero. They can be used in key components such as aircraft fuselages and wings, and have great application potential in the aviation field. This article describes the application of TPC in the aviation field, reviews the research progress of TPC, summarizes the key technologies and development trends of TPC, and finally summarizes and prospects the future development and challenges of TPC from the perspectives of materials, equipment, processes, and applications.

Research progress on multi-dimensional cross-classification system and engineering application of flexible composite pipes

LI Qing, FAN Huan, XU Han, LI Ruiying

2025, 0(8):  148-156.  DOI: 10.19936/j.cnki.2096-8000.20250828.018

Asbtract ( 22 )   PDF (4911KB) ( 277 )  

References | Related Articles | Metrics

Flexible composite pipes, as alternatives to traditional metal pipes, have attracted much attention in the fields of deep-sea oil and gas development and hydrogen energy transportation due to their advantages such as lightweight, corrosion resistance and high flexibility. This paper focuses on the material, structure and function of flexible composite pipes from a multi-dimensional cross perspective, and deeply analyzes the synergy mechanism among the three, aiming to provide a systematic reference for scientific research and practice in related fields. By sorting out the research trends of flexible composite pipes at home and abroad in recent years, this paper elaborates on the research progress from the classification system to the actual engineering application of flexible composite pipes, and at the same time makes prospects for the challenges and development directions it faces, in order to assist the continuous optimization and upgrading of infrastructure construction in the energy, chemical and other industries.