Static an‎d Dynamic Characterization of the Steel Sheets an‎d Calibration of Rate-dependent Ductile Fracture Model in Crash Simulation

9/23/2026 12:00:00 AM

In recent decades, enhancing safety an‎d optimizing fuel efficiency have emerged as two primary objectives in the automotive industry. The use of advanced high-strength steels, such as dual-phase steel DP590, provides an effective pathway toward achieving these goals. However, accurately predicting the behavior of such materials under severe dynamic loading conditions, particularly those induced by crash events, remains a complex engineering challenge. This study investigates the static an‎d dynamic properties of DP590 steel sheets an‎d calibrates a strain-rate-dependent ductile fracture model. To this end, a series of uniaxial tensile tests were conducted across a wide range of strain rates, from quasi-static to dynamic. Based on the experimental results, the constitutive an‎d fracture parameters of the Johnson–Cook model were successfully calibrated for DP590. In the next stage, square crash boxes—both plain (without holes) an‎d perforated—were fabricated to validate the calibrated model. These specimens were subjected to crushing tests under quasi-static loading (using a Sentam machine at constant speed) an‎d dynamic loading (using a dro‎p-weight impact system). The experimental procedures were complemented by numerical simulations performed in LS-DYNA using the calibrated material model. The results revealed excellent agreement between experimental an‎d numerical data for plain crash boxes. Nevertheless, the presence of geometric discontinuities such as holes introduced complex loading paths an‎d significantly broadened the oscillation range of the stress triaxiality parameter, thereby reducing the predictive accuracy of the model. This research provides the first complete an‎d validated set of Johnson–Cook parameters for DP590 steel an‎d establishes a direct mechanical link between stress-state complexity an‎d model prediction error in an industrial application. Dual validation under both quasi-static an‎d dynamic conditions further reinforces the reliability of the findings.

فولاد دوفازي DP590 , تحليل تصادف , مدل جانسون-كوك , جعبه تصادف , لهيدگي ديناميكي , پارامتر سه‌محوري تنش , LS-DYNA

Dual-phase steel DP590 , crash analysis , Johnson–Cook model , crash box , dynamic crushing , stress triaxiality , LS-DYNA

mina ajloo

ramin hashemi