Enrique Alcalá Fazio

Experimental protocol to assess the tourism vehicles accessibility based on heart rate and access time measurements.

The objective of the Project is to define an experimental protocol for the accessibility assessment of the transport vehicles, by analysing the evolution of the effort and time variables consumed by a target group –Persons of Reduced Mobility (PMRs). This protocol consisted in tests of accessibility on a sample of 6 passenger cars (class M1) by 8 elderly people carrying a heart rate monitor, and whose access manoeuvres were recorded by video cameras. Based on the Hilloskorpi et al. [1] model and by developing a method of truncation of the heart rate (HR) tests records - eliminating the component of the work biologically needed by the organism to keep its basal metabolic rate from the work each person performed – it was possible to evaluate how much energy each individual invested in each access manoeuver. Immediately after each test, and after the whole round of vehicles, each participant was surveyed for a subjective assessment of the difficulty of accessing to the cars. According to each of the above results, the HR objective measurements and the subjective opinion about the ease of access experienced by each individual, the vehicles were ranked by order of accessibility to the front and rear seats. The result of both rankings showed the orders of the similar vehicles, the potential of the method and a fair closeness between its results and the subjective, but real and unequivocal, judgments of the participants. DOI: http://dx.doi.org/10.4995/CIT2016.2016.3501

Evaluation of the seat fastening in the frame of a road bus submitted to frontal impact

The collective intercity transportation by bus is currently a mean of locomotion much sought after by people. Security in accidents is a very important factor that must be taken into account in design of bus body structure, being the evaluation of passenger safety of this type of vehicle is an important subject that should be checked, because in many accidents occur disconnection between seats and fastening members causing serious passengers injury, often fatal. This work aims at evaluation the behavior of frame fixing of seats of intercity bus bodies, submitted to the frontal impact situation in a rigid wall of 100% offset, through evaluation by finite element method (FEM). This study uses a numerical model corresponding to the body structure and chassis, developed through flexible beam elements, combining with shell elements for the structure of the seats and its fastening members, with the objective of not missing the essential aspects of the problem, allowing the solution with a reduced computational time. The numerical model of bus body and seat was impacted against a rigid wall at a speed of 8.89 m/s, being its validation according to the deceleration curve established by Regulation 80. Then it was gotten the Von Mises stress in fastening members of the seat structure in bus body. It is also presented a proposal to improve the fastening of the seat structure, comparing the results of the stress gotten in the two types fastening submitted to the frontal impact.

Behaviour of high bumper vehicles in pedestrian scenarios with full finite element human models

The European pedestrian regulations (formerly Directive 2003/102 and currently Regulation 2009/631 and recently modified by Commission Regulation [EU] No. 2011/459) have always approached the protection of lower extremities in pedestrian accidents with tests in the front part of the vehicle using rigid impactors. This approach offers a lot of advantage regarding the repeatability, robustness and reproducibility that these tests need but on the contrary decouple the injury occurrence through the different body areas. It is widely supported to approach pedestrian head protection and lower extremities protection in separate tests; however, there is not such consensus in decoupling pedestrian lower leg injuries from the upper leg injuries, especially in the case of high bumper vehicles. The objective of this paper is to look into the details of this close dependence through a set of simulations with THUMS 50th percentile male pedestrian finite element human model impacted by a wide set of high bumper vehicles. The analysis of both the kinematics and the injury occurrence in these scenarios has shown the strong coupling between the upper and lower leg injuries for this vehicle fleet, requiring therefore assessing both type of injuries at the same time.