RELIABILITY
During the early failure period, within hours of commencement of operation, it is quite likely that failures will occur due to various imperfections acquired during the manufacturing process, due to design faults or misuse. Gradually, these early failures will occur less frequently. This period is often covered by the manufacturers’ guarantee and ISO mark. ex: manufacturing fault in engine, rods, connector which causes affects failure rate.
The constant failure rate period is usually relatively long and the failure rate is normally approximately constant. During this period, it is usual for failures to occur at a relatively low rate but from a wide variety of causes. ex: wear and tear of wheel and increase in friction due to use of parts.
The beginning of the wear-out period corresponds to the end of the useful working life. All products wear out and this occurs because of a variety of time-dependant mechanisms. ex: puncturing of tyres, engine fails to run.
Reliability is time-dependant and is defined as a probability of failure.
It is unlikely to be for essential for every component to function correctly in order to ensure system success.
Ideally every component has to be checked or tested to know its maximum load. But as this isnt possible manufacturer guarantee regarding product is considered.
Critical components can be duplicated so that if failure occurs, there is a spare to take over-this is called Redundancy ex: placing 2 connectors.
Reliability can be increased by placing an alternative in series. When mishap happens 1 machine is lost it doesn't affect the working of other parts of the vehicle.
Factor of Safety
1. Load type and force analysis
The BRAIN is designed to carry a load of 100-150 passengers. Anything exceeding the specified number might affect certain aspects like decrease in the speed, excess fuel consumption, wearing out of tyres and discomfort caused to passengers, but on the whole, does not affect the functioning of the bus and safety in any way.
2. Stress analysis of critical sections
The vehicle is designed to handle a great amount of stress which enables the proper functioning of the separator.
3. Analysis of possible modes of component failure
Any technical snag in the engine may cause a break-down of the vehicle. Due to the usage of the tyres for a longer period, friction produced is high which eventually causes the tyres to burn out or puncture. Due to the excessive heat, the wires connecting the brakes may cut causing brake failure. During the case of emergencies, there is a possibility of failure of operation of the separator button thus causing a hindrance to people.
Cohesion means should how independent is the machine in taking the input and processing it. The fuel is taken from the tank and used in engine. The emitted gas is sent through exhaust pipe.
Coupling indicates the strength of link between the components. For input for the vehicle dependency on filling gas stations. But coupling is reduced by placing tankers that can hold compressed gas for long distances.
Ideally maximum cohesion and minimum coupling should be achieved. We have strived to achieve this in our vehicle.
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