PSI - Issue 48

Samira Belhour et al. / Procedia Structural Integrity 48 (2023) 288–295 Belhour et al/ Structural Integrity Procedia 00 (2019) 000 – 000

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4. Analysis and discussion From the results presented in Figure 5, we can see that the most critical trams are R111, R116 and R117. However, as the tram is composed of subsystems, we carried out a thorough study to determine which subsystems are most affected by failures. The application of the Pareto diagram allows us to classify undesirable causes in order of importance, or even allowed us to highlight the causes that generate the greatest number of disturbances, Figure 6.  For the year 2018: The analysis of the curve figure 6.a clearly shows that nine (09) subsystems representing a rate of 37.5% are responsible for 72.07% of the failures which are respectively the subsystems: Miscellaneous And Accessories, Adhesion restoration, Braking traction, lighting, Doors, Bogie Suspension, Friction braking, Train safety monitoring, HVAC, ROOM.  For the year 2019 : The analysis of the curve figure 6.b, shows clearly that eleven (11) subsystems represented by a rate of 45% are responsible for 82.44% of the failures which are respectively the following subsystems: Miscellaneous And Accessories, Braking traction, HVAC Cabin, Adhesion restoration, HVAC,ROOM, lighting, Friction braking, Doors, Visual information, Tacho control unit, Bogie Suspension  For the year 2020: The analysis of the curve figure 6.c, clearly shows that seven (7) subsystems (29%) are responsible for 64% of the failures which are respectively the following subsystems: Braking traction, lighting, Adhesion restoration, Miscellaneous And Accessories, Friction braking, Bogie Suspension, Doors  For the year 2021 : The analysis of the curve figure 6.d, clearly shows that seven (7) subsystems (29%) are responsible for 84.589% of the failures which are respectively the following subsystems: Adhesion restoration, Bogie Suspension, lighting, Braking traction, Doors, Miscellaneous And Accessories, Windshield wipers and washers, Friction braking. In order to carry out the study conveniently and to make the operation efficient, we have focused on the technical subsystems with a redundant safety character each year, namely: Traction Restoration, Friction Braking, Traction Braking, Bogie Suspension and the doors. Of course the same can be done for the other subsystems. Thus, to guide us in making the right decisions to improve the operational safety of the tramway and reduce the risk of failures or even accidents, we used a FMECA study, Table 1. This allows us to analyse the failure modes, their effects and their criticality. It helped us to identify anything that could not work in the process and, as a result, to eliminate all the probable causes of failures that could affect the smooth running of the tram and lead to the occurrence of risks.

2018

2019

0 10 20 30 40 50 60 70 80 90 100

0 10 20 30 40 50 60 70 80 90 100 cumulative number of failures (%)

Subsystems

Subsystems

cumulative number of failures (%)

SAE

Doors

TCMS

Doors

TCMS

lighting

lighting

Bodywork

PA system

PA system

Braking traction HVAC Cabin

HVAC Cabin

HVAC,ROOM

HVAC,ROOM

Friction braking

Driver exchange

Bogie Suspension Friction braking

Adhesion restoration Braking traction

Magnetic braking

Cases and inter cases Indoor monitoring

Flange lubrication

Visual information

Tacho control unit

Bogie Suspension

Cases and inter cases Flange lubrication Magnetic braking

Indoor monitoring

Visual information

Tacho control unit

Adhesion restoration

Windshield wipers and wa Train safety monitoring

Auxiliary energy supply

External access surveill Subsystems

Train safety monitoring

Auxiliary energy supply

External access surveill

Miscellaneous And Access

Windshield wipers and wa

X Axis Title

Miscellaneous And Access