Abstract
The paper presents the findings of the strain rate effect, described in constitutive material models by strain rate sensitivity index m, to the strength and deformation material properties. These were evaluated from stress-strain diagrams recorded at tensile test using PC controlled testing machine TiraTEST 2300 according to STN EN ISO 6892-1. The high strength low alloyed steel H220PD, dual phase steel DP 600 and Trip steel RAK 40/70 were investigated at strain rates = 0.0021, 0.083 and 0.125 s-1. The results indicate major influence of the strain rate to the strength properties while only minor influence have been found when evaluate the deformation properties. The results also shown single phase materials are more sensitive to the strain rate than dual phase materials.
Highlights
Technic evolution in present is characterised by effort to increase the cars’ safety and power as well as reduction of weight and emissions
2 Materials and methods The experiments were built to find out the strength and deformation properties of high strength steels – high strength low alloyed steel H220PD, Dual phase steel DP 600 and Trip steel RAK 40/70
The findings have shown the strength properties are more sensitive than deformation properties, within the quasistatic strain rate interval 0.0021 s-1 to 0.5 s-1
Summary
Technic evolution in present is characterised by effort to increase the cars’ safety and power as well as reduction of weight and emissions. This requires better understanding to the processes involved in materials when car impacts to the barrier or when components for deformation zones are produced; mainly at higher strain rates. The cars compatibility at accident depends mainly on each car weight, structure of deformation zones and deformation properties of materials used. When car frontally impacts deformable barrier at speed lower than 20 km/h, the impact energy have to be totally absorbed in controlled manner by car-body structure and materials used for components of deformation zones to secure the passengers’ safety – see Fig. 1. The strain rate raising, resistance to deformation increases as well and some materials have shown material micro- and sub-structure change [1, 2], yield strength and deformation to fracture growth [3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
