2 minute read
NSSA TECHNICAL | Brace for Impact on Security Screens
WORDS: Jack Ryan, NSSA Technical Committee Chair & NSSA Board Member
One of the key test factors of security screen compliance is the dynamic impact test as specified by Australian Standard (AS) 5041:2003 – Methods of Test – Security screen doors and window grilles. This test sends a sand and lead-filled bag, weighing around 40 kg, swinging towards and impacting a security screen at 100 joules of force. This is repeated five times.
The logic of the 100 joules impact test was about simulating a human kick with repeated attempts to force open a security screen from any weak connection point.
Historically written with diamond grille security in mind, it is fair to say we now know much more about measuring human physical force than ever before. From a product performance testing perspective, we already know modern security screens have been proven to withstand much higher impacts than the current 100 joule benchmark. These factors are being taken into account by the Standards Australia Committee CS-023 as they review and refine the new Australian Standards for our industry.
Working in collaboration with some of Australia's great minds at James Cook University and Curtin University, calculations have been prepared on what the modern human body is capable of exerting when joule(s) is concerned.
The impact-energy modelling highlights that an individual with a body weight of 115 kg has the ability to expel 200 joules via a kick method and 220 joules via a hip and shoulder method.
Dynamic impact testing of a security screen door.
IMAGE: Azuma Design
It is always important to allow for a tolerance to accommodate an individual highly-trained in martial arts exceeding this energy estimate and/or the potential absorption by the dynamic impact testing projectile in a test rig scenario. Knowing these insights helps us plan for the future and gives us scientific justification in that the minimum joule level of 100 needs to be lifted.
Security screens protect our family members and the community, and we need to ensure that when a product is tested it can withstand real world conditions, such as the above impact energy scenario. One thing is for certain, the NSSA wants the updated Australian Standard of the future to be one we as an industry are proud of, data backed, highly credible, and with strong industry consultation.
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