مشخصات پژوهش

عنوان	Determination of stress–strain curves of materials at high strain rates using dynamic indentation technique
نوع پژوهش	مقاله چاپ‌شده در مجلات علمی
کلیدواژه‌ها	Dynamic indentation test, Johnson–Cook model, high strain rates, load–depth curve, Hopkinson bar
چکیده	Determination of dynamic behaviour of materials is a serious challenge in mechanics of materials. In this investigation, a new approach is proposed to obtain stress–strain curves of metals from dynamic indentation test. This approach is based on a combined experiment, simulation, and optimization techniques. In the experiment side, a conical penetrator is shot against the material as the target. The load–indentation depth curve is obtained from the dynamic indentation test. The indentation test is simulated using Ls-dyna and the numerical load–indentation depth is obtained from the simulation. The stress–strain curves are defined by Johnson–Cook material model. From optimization of the difference between the experimental and numerical load–indentation depth curves, the constants of the material model are identified. The material model is validated also by stress–strain curves obtained from quasi-static test conducted using Instron and dynamic tests conducted using Split Hopkinson Bar. The results show a close agreement between the model prediction and the experimental stress–strain curves for different strain rates.
پژوهشگران	سمانه پورالعجل (نفر اول)، غلامحسین مجذوبی (نفر دوم)