E Esmizadeh - Assistant Professor, Department of Polymer Science and Engineering, Faculty of Engineering, University of Bonab, P.O. Box ۵۵۵۱۷۶۱۱۶۷, Bonab, Iran
A Vahidifar - Assistant Professor, Department of Polymer Science and Engineering, Faculty of Engineering, University of Bonab, P.O. Box ۵۵۵۱۷۶۱۱۶۷, Bonab, Iran
G Naderi - Professor, Faculty of processing, Iran Polymer and Petrochemical Institute, P.O. Box ۱۴۹۷۵-۱۱۲, Tehran, Iran
A Varvani-Farahani - Professor, Department of Mechanical Engineering, ۳۵۰ Victoria Street, Toronto, Ontario, M۵B ۲K۳, Canada

High stress durable fiber-reinforced NR/SBR composites were prepared by melt compounding process. Both monotonic and fatigue properties of composites were noticeably improved as fiber volume fraction increased. Various hyper-elastic models were employed to evaluate the monotonic stress-strain response of the composites. Predictedresults by Arruda-Boyce and Yeoh models showed more deviation from experimental data with increasing fiber content, while Ogden and Marlow models were applicable for various fiber contents. Results of ratcheting tests showed that incremental progress in ratcheting strain stayed constant after some stress cycles forming a plateau. The formation of plateau was found to be dependent on the fiber volume fraction. Experiments showed that the plateau occurred at 48th cycle for NR/SBR blends with fiber volume fractions of 30%. While samples with no fiber content fractured at 3rd cycle without a plateau response in data.

Blends, Fiber-reinforced composites, Hyper-elastic models, Nylon short fibers, Ratcheting