M.J. Schuurman
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22 records found
1
Air Safety Investigation
The Journey
Modelling head injury due to unmanned aircraft systems collision
Crash dummy vs human body
Recent developments in the concept of UAS operations in urban areas have led to risk concerns of UAS collision with human. To better understand this risk, head and neck injuries due to UAS collisions have been investigated by different research teams using crash dummies. Because of the limitations in biofidelity of a crash dummy, head injury level for a crash dummy impact may differ from the human body impact. Therefore, the aim of this paper is to investigate differences in head and neck injuries subject to UAS collision between an often-used Hybrid III crash dummy and a human body. To perform such investigation, multibody system (MBS) impact models have been used to simulate UAS impacts on validated models of the Hybrid III crash dummy and the human body at various impact conditions. The findings show that the Hybrid III predicts similar head and neck injury compared to the human body when UAS collides horizontally from front and rear. However, the Hybrid III over-predicts head injury due to horizontal side impact. Moreover, under vertical drop and 45 degree elevated impact of UAS, the Hybrid III under-predicts head injury, and over-predicts neck injury.
Evaluating safety risk posed to third parties on the ground due to UAS impact requires a model of probability of fatality (PoF) for human. For quadrotor UAS, the existing impact models predict remarkably different PoFs. The most pessimistic is the impact model adopted by Range Commanders Council (RCC) while the Blunt Criterion model is far more optimistic. The ASSURE study has assessed the third set of PoF values through conducting controlled drop tests of a DJI Phantom III on a crash dummy; these results differ again. To investigate these discrepancies, this paper employs a numerical impact analysis of UAS collisions on humans. The current paper is the third in a series of studies. The first study developed a MultiBody System (MBS) simulation model of a DJI Phantom III impacting the head of a crash dummy; this MBS model has been validated against the experimental drop test results of ASSURE. The second study conducted simulations with the validated MBS model to systematically show the differences in head and neck injuries if the human dummy is replaced by a validated MBS model of a human body. The aim of the current paper is threefold: i) to extend the latter MBS model to assess injury levels for DJI Phantom III impact on thorax and abdomen; ii) to transform the assessed injury levels for head, thorax and abdomen to PoFs; and iii) to compare the MBS obtained PoFs to those from RCC and Blunt Criteria models. The MBS based results show that variations in the scenario of DJI Phantom III impact on the head significantly affect PoF. These variations are not captured by the RCC or BC model, and neither in the ASSURE measurements. Both for head, thorax and abdomen, in case of comparable impact scenarios, the RCC model tends to over-predicts PoF compared to the MBS model, while the BC model tends to under-predict PoF.
Modelling head injury due to unmanned aircraft systems collision
Crash dummy vs human body
UAS will be integrated into the airspace in the near future, but the risk of UAS collision is not well understood which hampers the development of adequate regulations and standards. As risk has two constituents: frequency and consequence, collision risk analysis of UAS operations in future UTM asks for a quantitative assessment of various types of frequency and consequence. However, prior to studying such quantitative assessment, it is a prerequisite to identify the various types of collisions and consequences. Doing the latter is the objective of this paper. This paper follows a step-wise approach in identifying the various types of collision consequence under a given UTM ConOps, focusing on the very-low-level UAS operations. The first steps address the analysis of the UTM ConOps, rules, and infrastructure considered, and the identification of types of objects and UASs that will operate in the very-low-level UTM system. The follow-up steps are to characterize impact materials by applying zone of impact analysis, followed by analyzing the types of collision consequence. The result is a systematic identification and characterization of types of collision consequences as well as applicable impact materials and conditions that will form the basis for safety risk analysis in follow-on research.
Increasing Bloom’s Hierarchical Learning in Aerospace Engineering
A Case Study of Forensic Engineering Course using a “Chain of Events”
A Paradigm Shift in Teaching Aerospace Engineering
From Campus Learners to Professional Learners – a Case Study on Online Courses in Smart Structures and Air Safety Investigation
for forensic investigations. This integrated approach consists of three elements. First, because a product has a life cycle with various phases, it is of importance to consider these phases when a failure is investigated. Second, it is
acknowledged that failure is a multifaceted phenomenon. Therefore, the ‘Tree House of Failures’ was developed, a taxonomy or categorisation of failure causes, which addresses main groups of causes of failure related to product,
instruction and execution. Third, use of a standard investigative approach with the steps ‘orientation’, ‘data collection’, ‘hypotheses generation’, ‘hypotheses testing’, ‘recommendations’ and ‘findings reporting’ is advised. In the Delft approach, the ‘ring of trustworthiness’ is used to underline the mind-set that a forensic engineering investigator should have to assure the investigation’s reliability and validity. The ring of trustworthiness states that an investigation should be objective, repeatable, verifiable, complete and correct. This paper presents the Delft approach for forensic investigations and explains how to use it to prevent several common pitfalls and biases that occur in various stages of a forensic engineering investigation. This approach aims to increase the reliability of forensic engineering investigations worldwide. ...
for forensic investigations. This integrated approach consists of three elements. First, because a product has a life cycle with various phases, it is of importance to consider these phases when a failure is investigated. Second, it is
acknowledged that failure is a multifaceted phenomenon. Therefore, the ‘Tree House of Failures’ was developed, a taxonomy or categorisation of failure causes, which addresses main groups of causes of failure related to product,
instruction and execution. Third, use of a standard investigative approach with the steps ‘orientation’, ‘data collection’, ‘hypotheses generation’, ‘hypotheses testing’, ‘recommendations’ and ‘findings reporting’ is advised. In the Delft approach, the ‘ring of trustworthiness’ is used to underline the mind-set that a forensic engineering investigator should have to assure the investigation’s reliability and validity. The ring of trustworthiness states that an investigation should be objective, repeatable, verifiable, complete and correct. This paper presents the Delft approach for forensic investigations and explains how to use it to prevent several common pitfalls and biases that occur in various stages of a forensic engineering investigation. This approach aims to increase the reliability of forensic engineering investigations worldwide.
Reengineering history
What can we learn from a photographed B-17 “Flying Fortress” in-flight structural failure?