Temperature Dependence Study Of Carbon Black Filled Rubber Hyperelasticity

Carbon black is currently the most widely used reinforcing agent in the rubber industry.Due to their excellent properties,carbon black filled rubber composites are widely used in tires,vibration isolators,seals and bushings.However,the self-heating nature of rubber components exposed to high temperatures or cyclic loading increases the temperature,thus seriously affecting their mechanical properties.Therefore,it is particularly important to investigate the mechanical properties of rubber composites for practical production and design.This paper investigates the temperature dependence of the hyper-elastic mechanical behavior of rubber composites over a large deformation range(150% strain).The aim was to investigate the effect of temperature and cyclic loading and unloading on the hyper-elastic mechanical behavior of carbon black filled rubber.The main research work and results are summarized as follows:(1)The effect of different carbon black fillings on the hyper-elastic mechanical behavior of natural rubber over a wide range of deformations is investigated.The carbon black fillings influence the steepness of the stress-strain curve of carbon black filled rubber.A quantitative relationship was established between the material parameters and the volume fraction of carbon black in the Yeoh constitutive model.In this way,a method for calculating the material parameters of the Yeoh constitutive model is developed,which can predict the correlation between the hyper-elastic mechanical behavior of rubber and the volume fraction of carbon black filling.(2)To investigate the cyclic tensile hyper-elastic mechanical behavior of rubber composites with different carbon black fillings under the influence of temperature,a variable temperature electronic universal testing machine was used to load carbon blackfilled rubber(including pure rubber)with a history of deformation in a "stepwise" manner,and uniaxial cyclic tensile loading and unloading experiments at different temperatures such as 293 K,313K,333 K,353K,363 K and 383 K were completed.A comparison of the cyclic tensile stress-strain curves of rubber specimens with different carbon black fillings at varying temperatures reveals that the reinforcing effect of carbon black on the rubber matrix gradually weakens with increasing temperature,and this weakening trend is quantitatively characterized by the stress maxima and stress amplification factors at different loading sections,revealing the different effects of temperature variation and carbon black content on the cyclic tensile hyper-elastic behavior of rubber composites.(3)Uniaxial tensile experiments were carried out on rubber composites(including pure rubber)with different carbon black fillings at different temperatures over a wide range of deformations.By comparing the adaptability of different constitutive models to their stress-strain variation patterns with temperature,it is concluded that the material parameters of the Yeoh constitutive model are temperature dependent,and a form of the Yeoh constitutive model based on the continuum media mechanics is constructed with an explicit temperature,and the ability of the Yeoh constitutive model with an explicit temperature to characterize rubber with different carbon black fillings at different temperatures is investigated by finite element analysis.