مشخصات پژوهش

عنوان	A constitutive model for hardness considering the effects of strain, strain rate and temperature
نوع پژوهش	مقاله چاپ‌شده در مجلات علمی
کلیدواژه‌ها	Hardness, strain rate, strain, Taylor test, Hopkinson bar
چکیده	The relation between hardness, strain and temperature has been widely investigated over the past decades. However, less attention has been paid to the effect of strain rate on hardness induced in high rate deformations. In this investigation, the relation between strain, temperature and strain rate is studied and a new model is proposed. The investigation is performed by experiment and numerical simulation. The simulations are used to predict the distribution of the strain and strain rate within the specimen. The high rate experiments are conducted using Taylor test, compressive and tensile Hopkinson bar. Quasi-static tests are also carried out using Instron testing machine. The results show a quadratic relation between the hardness and strain rate. The results also indicate that the relation between hardness, strain and temperature is the same for the compressive and tensile loading but the relation between hardness and strain rate is different for the compression and tension. The hardness increases with the increase of the strain and strain rate but decreases with the temperature. The reason is believed to be due to dislocation pile up which is denser in compression than that in tension
پژوهشگران	غلامحسین مجذوبی (نفر اول)، جمال محمدی (نفر دوم)، محمد پیپل زاده (نفر سوم)، سعید لحمی (نفر چهارم)، استفان هاردی (نفر پنجم)