Special Contribution

• LIU Guijie,ZOU Bo,DING Xingwu,BU Jiling,ZOU Jicao and ZHOU Min
• Study on Dynamic Performance of Rubber-liquid Composite Spring for Rail Vehicle

• 2025 Vol. 72(11): 0803-0811

  [Abstract](66)

  [PDF](48)

• Abstract:he dynamic performance of the rubber-liquid composite spring for rail vehicles（referred to as composite spring） was studied.The theoretical calculation of the dynamic performance of the composite spring mainly adopted a lumped parameter model，and the key parameters of the model were the rubber main spring parameter，the liquid chamber volume stiffness，the inertia channel parameter and initial state parameter，which were determined by the rubber main spring structure，inertia channel structure and load etc，reflecting the comprehensive influence of rubber main spring structure，liquid damping and load on the dynamic performance of the composite spring.Compared with the experimental values，the error of the peak dynamic stiffness of the composite spring using the simulation calculation method was 10.6%，and the error of the peak loss angle was 3.6%，indicating high simulation calculation accuracy.The influence of key parameters of the composite spring on the dynamic performance was mainly reflected in the peak dynamic stiffness and peak loss angle and their corresponding frequencies.This study could provide reference for the design and application of composite springs.

Applied Theory

• DING Lei and DING Xiaodong
• Molecular Dynamics Simulation Study on Effect of Acrylonitrile Contents on Properties of NBR

• 2025 Vol. 72(11): 0812-0819

  [Abstract](81)

  [PDF](49)

• Abstract:Based on the OPLS force field，the effect of acrylonitrile contents on the microstructures，dynamic properties and mechanical properties of nitrile rubber（NBR） was studied using full atomic molecular dynamics simulation.The results showed that with the increase of acrylonitrile content，the interaction force between NBR molecular chains increased，the molecular chain segments were more tightly packed，the mean-square radius of gyration and mean-square end-to-end distance of NBR molecular chain increased at first and then decreased，the mean-square displacement decreased，the mobility of chain segments was reduced，the density of NBR increased，the glass transition temperature was improved，and the tensile stress and elastic modulus increased.When the acrylonitrile content was greater than 33.3%，the tensile stress and elastic modulus of NBR increased sharply，mechanical properties were significantly improved.

• ZHU Lianchao,SHI Wencang and WANG Xian
• Construction of A Mathematical Model of The EPDM Compound Recipe Based on Customized Response Surface Methodology

• 2025 Vol. 72(11): 0820-0825

  [Abstract](85)

  [PDF](42)

• Abstract:Customized Response Surface Methodology (RSM) is applied to investigate the influence of carbon black and paraffin oil on the processability and physical and mechanical properties of ethylene-propylene rubber (EPDM) compound and a mathematical model is constructed based on design of experiment and analysis of variance (ANOVA). In the mathematical model, 7 fitting equations have been established by means of linear or 2 factorial interactions which is significant with p<0.05 and goodness of fit >0.90. The above mathematical model can be applied to find a suitable range of carbon black and paraffin oil based on the desired performance of the compound. The actual experimental results are highly consistent with the desired performance within 5% error. The customized RSM can be applied to more factorial to support the EPDM compound design which has an excellent application extensibility.

• Yang Qingjing,QI Wang-bin,SU Dong-fang,XI Ke-hui,SI Wen-kai,LIU Yang,HU Ze-tao,YUAN Xin-wei,LI Zhuang-you and SU Zi-hang
• Effect of carbon black particle size and structure on the static and dynamic mechanical properties of styrene butadiene rubber

• 2025 Vol. 72(11): 0826-0832

  [Abstract](99)

  [PDF](59)

• Abstract:The effects of the particle size and structure of carbon black N110, N220, N234, N774, and DZ-13 on the static and dynamic mechanical properties of carbon black filled styrene butadiene rubber (SBR) composites were studied. The results showed that the SBR filled by carbon black with small primary particle size and high structure, such as N234, exhibits a high mechanical strength and wear resistance but has a high dynamic hysteresis due to the high value of tan ? at 60 ℃. Since N774 has the largest particle size and the lowest structure among the five types of carbon black, it filled SBR composite has the lowest rolling resistance and the highest wet skid resistance, while its mechanical strength and wear resistance are poor. For DZ-13, its primary particle size is slightly larger than that of N110, N220, and N234, which may lead to the decrease of the mechanical strength of its SBR composite. However, its high structure compensates this short coming and the SBR filled by DZ-13 exhibits a mechanical strength and wear resistance comparable to that of N110 and N220, and is only slightly lower than that of N234. In addition, its relatively high aggregate size makes its SBR composite has low rolling resistance and dynamic temperature rise.

Material · Compounding

• LIU Yuliang,LIN Siqing,HU Jinjin and FANG Yuan
• Study on Properties of Domestic Easily Processable Rare Earth BR

• 2025 Vol. 72(11): 0833-0838

  [Abstract](79)

  [PDF](42)

• Abstract:The properties of domestic easily processable rare earth（neodymium） cis-polybutadiene rubber（NdBR） TF45E were studied and compared with domestic ordinary NdBR9104 and foreign easily processable NdBR CB25.The results showed that compared with NdBR9104，NdBR TF45E had similar molecular weight and its distribution，but had a longer Mooney stress relaxation time.The processability of NdBR TF45E compound was better than NdBR9104 compound，comparable to NdBR CB25 compound，and the wear resistance and flexibility resistance of NdBR TF45E vulcanizate was excellent.NdBR TF45E could replaced NdBR CB25 in tire tread and siedwall compounds.

• Zhang Rifen and Ai Xiangren
• Study on Preparation and Properties of Fiber-reinforced Rubber Matrix Sealing Materials for Building Joints

• 2025 Vol. 72(11): 0839-0843

  [Abstract](81)

  [PDF](43)

• Abstract:The preparation and properties of the fiber-reinforced rubber matrix sealing materials for building joints were studied.Experiments showed that the optimized formula（dosage/phr）of the fiber-reinforced rubber matrix sealing material was：rubber（natural rubber/nitrile rubber dosage ratio of 1/4）　35，fibers（aramid fiber/mineral fiber dosage ratio of 1/2）　15，fillers（silica/kaolin/calcium carbonate/mica powder/barium sulfate dosage ratio of 6/14/11/5/9）　45，other compounding agents [vulcanizing agents（including sulfur dichloride and dibenzoyl peroxide）/accelerator M/activators（including zinc oxide and diethylene glycol） dosage ratio of 2.5/0.5/2]　5.The tensile strength of the optimized formula fiber-reinforced rubber matrix sealing material decrease minimally with increasing tensile rate.Meanwhile，its creep relaxation and the mass loss rates after immersion in water，saturated calcium hydroxide solution and sodium chloride solution were the minimized.This indicated that the optimized formula fiber-reinforced rubber matrix sealing material had the best tensile properties，creep relaxation resistance and liquid corrosion resistance.

Product · Design

• CHANG Hao,LI Yu,YE Amin,XU Mingyi,GE Qi and CHENG Haitao
• Structure Design of a Variable Stiffness Lateral Stop for Rail Vehicle

• 2025 Vol. 72(11): 0844-0850

  [Abstract](76)

  [PDF](38)

• Abstract:Structure design of a variable stiffness lateral stop for railway vehicle（referred to as lateral stop） with tower shaped structure was carried out based on finite element analysis.The rubber part of the lateral stop adopted a two-stage streamlined surface combination，which could optimize the shape of the rubber part after being loaded and avoid the rubber part breakage.By changing the size and shape of the bottom hole of the lateral stop and the height of the plate sidewall of the metal bottom，the position of the stiffness inflection point could be flexibly adjusted to better meet the design requirements.The type test verified the reliability of the tower shaped structure of the lateral stop.This design could provide reference for the structure development of lateral stop.

Technology · Equipment

• ZHAO Jinyang,CHAI hailin,JIAN Xing’ao,LIU Kexin,YANG Chongzhi,HU Songjie,LIU Fumin,XU Yuan,LIU Haichao and GUO Lei
• Research on Regeneration of Waste Rubber Based on Monoterpene Environmentally Friendly Swelling Additive and ScCO₂ Synergistic Swelling

• 2025 Vol. 72(11): 0851-0858

  [Abstract](72)

  [PDF](28)

• Abstract:The regeneration（low-temperature mechanical-chemical regeneration） process conditions of waste rubber（waste rubber tire tread compound strip） based on monoterpene environmentally friendly swelling additive and supercritical carbon dioxide（ScCO₂） synergistic swelling were experimentally studied.The results showed that the optimized regeneration process conditions of waste rubber（in a high-pressure reaction vessel） based on monoterpene environmentally friendly swelling additive and ScCO₂ synergistic swelling were as follows：the dosage of monoterpene environmentally friendly swelling additive　2 phr，reaction temperature　100～120 ℃，reaction pressure　8～10 MPa，reaction time　15～20 min.Compared recycled rubber compounds prepared by the traditional regeneration process of waste rubber，the recycled rubber compounds prepared by the regeneration process of waste rubber based on monoterpene environmentally friendly swelling additive and ScCO₂ synergistic swelling exhibited significant advantages in terms of Mooney viscosity，vulcanization characteristics，tensile properties and dynamic mechanical properties.

• WANG He,CHU Qingchen,LIU Tong,WANG Zhifei and BIAN Huiguang
• Design of Asymmetric Rotor for Mixer and Its Simulation Analysis and Application Research

• 2025 Vol. 72(11): 0859-0869

  [Abstract](80)

  [PDF](44)

• Abstract:The asymmetric rotor for the mixer was designed，and the simulation analysis and application research on the mixing processes of two asymmetric rotors and two synchronous four-wing rotors in 0°，90° and 180° phase relationships were carried.The simulation analysis showed that，when the mixing time were 5，10，15 s，the two asymmetric rotors in 90° and 180° phase relationships exhibited nearly identical dispersion effects on natural rubber （NR） particles and carbon black N330 particles.The application research showed that，when the filling coefficient of mixer was identical，the discharge temperatures corresponding to the two asymmetric rotors and the two synchronous four-wing rotors in 0°，90° and 180° phase relationships displayed negligible differences.When the filling coefficient of mixer was 0.65，the Mooney viscosity of the compound corresponding to the two asymmetric rotors in 180° phase relationship was the minimum，thet₉₀ was shortest，the carbon black dispersion，F_max－F_L，Shore A hardness，modulus at 100 %，modulus at 300%，tensile strength and tear strength were the maximum，and the elongation at break of the compound corresponding to the two asymmetric rotors in 90° phase relationship was the maximum.

Comprehensive and Special Review

• HU Debin,SU Benlong,WU Jian,WANG Yi,WANG Youshan and WANG Jianbo
• Research Progress on Testing and Prediction of Tire Rolling Resistance

• 2025 Vol. 72(11): 0870-0879

  [Abstract](92)

  [PDF](51)

• Abstract:The testing methods of tire rolling resistance and the applicable conditions of various methods were reviewed.Through comparison，it was found that the whole vehicle testing operation for tire rolling resistance was more difficult than indoor testing operation，but it could better reflect the influence of the road and environmental conditions on tire rolling resistance，but the laboratory drum testing had better reproducibility and stability than those of vehicle testing.The prediction models of tire rolling resistance were analyzed，the characteristics of equivalent simplified models，including empirical models，analytical models，thermal models，force models and thermal coupling models were compared，and various numerical calculation model equations were listed.The future development trends of tire rolling resistance testing and prediction were pointed out.