Analysis of the performance of different architectures of forward facing CRS with integral restraint system

Johannsen, Heiko; Beillas, Philippe; Lesire, Philippe

Affiliations

²Université de Lyon, F-69622, Lyon, France ; IFSTTAR, LBMC, UMR_T9406, F-69675, Bron; Université Lyon 1,Villeurbanne

³LAB PSA Peugeot-Citroën/Renault, France

Abstract

The use of an appropriate Child Restraint Systems (CRS) is mandatory in Europe for children up to at least 135 cm. CRS are currently homologated according to the regulation ECE R44. A draft for a new ECE Regulation has been proposed. According to ECE R44, children with a weight between 9 and 18 kg shall use a CRS with integral restraint system, which are normally forward facing. Two architectures fulfilling the integral restraint system requirements can be found on the European market: 5-point-harness systems and shield systems. In principle the same systems can be homologated according to the future regulation.

While shield systems were very popular in the beginning of the CRS epoch, they disappeared in the end of the 1990s. Today they are subject of a revival. Although a considerable number of shield systems are offered in the market today and it is estimated that they have today a market share of 10% of the CRS group in question, they are seldom observed in field data, i.e. accident data and misuse studies, and biomechanical studies on the topic are limited.

The aim of this study was to analyse the performance of shield and harness systems in dummy tests, to analyse the limited accident data available and discuss the possible impact on future child safety.

While shield systems are advertised to protect the neck better than 5-point harness systems, this is overall not supported by the test results, especially for neck moments which appear to be higher with shield systems for most of the tests. However, for the long duration ADAC pulse shield systems show clearly lower neck loadings. Based on the observed injuries, it is questionable whether or not the Q dummy neck instrumentation is sufficient to fully understand the injury mechanisms. Mainly small children in forward facing CRS are suffering from neck injuries. These are mainly represented by Q1 and Q1.5. These dummies only offer upper neck load cells, which is in principle compliant with the injury pattern observed for this age group. However, lower neck injuries are appearing to be more of an issue for shield systems.

Dummy readings are also considerably higher for thorax and abdomen for shield systems than 5-point-harness systems. Based on the limited accident data available, this seems associated with more frequent injury to these regions with shields.

The head excursion, an important factor for head injuries, is lower for shield systems than for 5- point-harness systems in dummy tests.

Overall, the results from the current study do not clearly indicate a benefit of shields for the head and neck. However, they raise questions about possible risks to the thorax and the abdomen.

Links

URL: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv23/23ESV-000226.pdf

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Cited By (1)

Year	Entry
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