IIHS side impact parametric study using LS-DYNA
Reichert, R / Kan, S / Arnold-Keifer, S / Mueller, Becky C.
Proceedings of the 15th International LS-DYNA Users Conference
June 2018
Abstract
Side impact crashes are the second most common reason for vehicle passenger deaths after frontal crashes. In 2003, the Insurance Institute for Highway Safety (IIHS) introduced its side impact crash test using a Moving Deformable Barrier (MDB) to encourage manufacturers to implement safety improvements, including side airbag coverage and stronger side structures, in most vehicle models. While many vehicles were rated poor in the beginning of testing in 2005, most of the vehicles were rated good in 2015. Improved IIHS ratings are associated with a more than 30% reduction in passenger deaths in multiple-vehicle side impact crashes. Of the remaining fatal side impact crashes, the majority are occurring at a more forward impact location and higher severity compared to the IIHS test. For this reason, the IIHS is planning a series of full-scale tests to evaluate the effect of different impacting vehicles and test setups with respect to today’s test protocol. For reducing costly, time-consuming, and complex full-scale testing, finite element (FE) simulations play an important role and are successfully used in vehicle safety research and development. Therefore, the aim of this study was to complement the ongoing IIHS full-scale side impact crash test study with FE simulations. This study features a validated FE model of a 2015 midsize sedan as the target vehicle in the IIHS test configuration. The parametric study varied bullet vehicle characteristics: bullet vehicle velocity (50 km/h vs. 60 km/h), bullet vehicle mass, and impact location relative to the target vehicle’s occupant compartment. Available bullet vehicle models represent small and midsize passenger cars, sport utility vehicles (SUVs), and pickups in addition to a model of the standard IIHS MDB. Impact severity of the target vehicle was assessed from measures of maximum lateral B-pillar intrusion relative to the driver-seat centerline, used for calculating IIHS structural ratings, B-pillar peak lateral velocity, and maximum crush of the door at chest and pelvic height. In the standard IIHS configuration, the MDB was more severe than the small and midsize cars, but less severe than the midsize SUV or pickup. Aspects of the MDB’s geometry make its impact pattern more SUV-like, but a lower mass decreases the severity. Increasing the MDB mass to 2,000 kg resulted in structural intrusions more similar to the midsize SUV. At the higher velocity of 60 km/h, the bullet vehicles produced structural intrusions ranging from good to poor ratings. Either a higher mass striking vehicle or greater impact speed can be used to create a more severe impact configuration, with the higher impact speed having a greater effect. An evaluation of more forward impact locations indicated that the most structurally challenging impact location was at the current IIHS configuration, not farther forward. This parametric study provided insights into the types of crash configuration changes IIHS may consider when conducting full-scale research tests developing a higher severity side impact test to address real-world injured occupants in good-rated vehicles.
Side impact crashes are the second most common reason for vehicle passenger deaths after frontal crashes. In 2003, the Insurance Institute for Highway Safety (IIHS) introduced its side impact crash test using a Moving Deformable Barrier (MDB) to encourage manufacturers to implement safety improvements, including side airbag coverage and stronger side structures, in most vehicle models. While many vehicles were rated poor in the beginning of testing in 2005, most of the vehicles were rated good in 2015. Improved IIHS ratings are associated with a more than 30% reduction in passenger deaths in multiple-vehicle side impact crashes. Of the remaining fatal side impact crashes, the majority are occurring at a more forward impact location and higher severity compared to the IIHS test. For this reason, the IIHS is planning a series of full-scale tests to evaluate the effect of different impacting vehicles and test setups with respect to today’s test protocol. For reducing costly, time-consuming, and complex full-scale testing, finite element (FE) simulations play an important role and are successfully used in vehicle safety research and development. Therefore, the aim of this study was to complement the ongoing IIHS full-scale side impact crash test study with FE simulations. This study features a validated FE model of a 2015 midsize sedan as the target vehicle in the IIHS test configuration. The parametric study varied bullet vehicle characteristics: bullet vehicle velocity (50 km/h vs. 60 km/h), bullet vehicle mass, and impact location relative to the target vehicle’s occupant compartment. Available bullet vehicle models represent small and midsize passenger cars, sport utility vehicles (SUVs), and pickups in addition to a model of the standard IIHS MDB. Impact severity of the target vehicle was assessed from measures of maximum lateral B-pillar intrusion relative to the driver-seat centerline, used for calculating IIHS structural ratings, B-pillar peak lateral velocity, and maximum crush of the door at chest and pelvic height. In the standard IIHS configuration, the MDB was more severe than the small and midsize cars, but less severe than the midsize SUV or pickup. Aspects of the MDB’s geometry make its impact pattern more SUV-like, but a lower mass decreases the severity. Increasing the MDB mass to 2,000 kg resulted in structural intrusions more similar to the midsize SUV. At the higher velocity of 60 km/h, the bullet vehicles produced structural intrusions ranging from good to poor ratings. Either a higher mass striking vehicle or greater impact speed can be used to create a more severe impact configuration, with the higher impact speed having a greater effect. An evaluation of more forward impact locations indicated that the most structurally challenging impact location was at the current IIHS configuration, not farther forward. This parametric study provided insights into the types of crash configuration changes IIHS may consider when conducting full-scale research tests developing a higher severity side impact test to address real-world injured occupants in good-rated vehicles.
Abstract
Side impact crashes are the second most common reason for vehicle passenger deaths after frontal crashes. In 2003, the Insurance Institute for Highway Safety (IIHS) introduced its side impact crash test using a Moving Deformable Barrier (MDB) to encourage manufacturers to implement safety improvements, including side airbag coverage and stronger side structures, in most vehicle models. While many vehicles were rated poor in the beginning of testing in 2005, most of the vehicles were rated good in 2015. Improved IIHS ratings are associated with a more than 30% reduction in passenger deaths in multiple-vehicle side impact crashes. Of the remaining fatal side impact crashes, the majority are occurring at a more forward impact location and higher severity compared to the IIHS test. For this reason, the IIHS is planning a series of full-scale tests to evaluate the effect of different impacting vehicles and test setups with respect to today’s test protocol. For reducing costly, time-consuming, and complex full-scale testing, finite element (FE) simulations play an important role and are successfully used in vehicle safety research and development. Therefore, the aim of this study was to complement the ongoing IIHS full-scale side impact crash test study with FE simulations. This study features a validated FE model of a 2015 midsize sedan as the target vehicle in the IIHS test configuration. The parametric study varied bullet vehicle characteristics: bullet vehicle velocity (50 km/h vs. 60 km/h), bullet vehicle mass, and impact location relative to the target vehicle’s occupant compartment. Available bullet vehicle models represent small and midsize passenger cars, sport utility vehicles (SUVs), and pickups in addition to a model of the standard IIHS MDB. Impact severity of the target vehicle was assessed from measures of maximum lateral B-pillar intrusion relative to the driver-seat centerline, used for calculating IIHS structural ratings, B-pillar peak lateral velocity, and maximum crush of the door at chest and pelvic height. In the standard IIHS configuration, the MDB was more severe than the small and midsize cars, but less severe than the midsize SUV or pickup. Aspects of the MDB’s geometry make its impact pattern more SUV-like, but a lower mass decreases the severity. Increasing the MDB mass to 2,000 kg resulted in structural intrusions more similar to the midsize SUV. At the higher velocity of 60 km/h, the bullet vehicles produced structural intrusions ranging from good to poor ratings. Either a higher mass striking vehicle or greater impact speed can be used to create a more severe impact configuration, with the higher impact speed having a greater effect. An evaluation of more forward impact locations indicated that the most structurally challenging impact location was at the current IIHS configuration, not farther forward. This parametric study provided insights into the types of crash configuration changes IIHS may consider when conducting full-scale research tests developing a higher severity side impact test to address real-world injured occupants in good-rated vehicles.Crash testing and crashworthiness: Side crashes, ID: 2165