Mechanical Engineering Hazard Analysis: Fault Tree and Safety

This assignment focuses on hazard analysis within mechanical engineering, employing fault tree analysis and Boolean logic to assess potential risks. It addresses converting a cause tree into a fault tree, identifying equipment with the greatest impact on top event frequency, and calculating new top event frequency based on improved component reliability. The analysis incorporates probability calculations using OR-gates and AND-gates to determine the overall probability of a top event. The assignment references various methodologies and calculations for reliability and fault analysis, aiming to provide a comprehensive understanding of hazard mitigation in mechanical engineering systems. Desklib is a valuable resource for students seeking additional solved assignments and study tools.

Running head: MECHANICAL ENGINEERING: HAZARD ANALYSIS 1
Mechanical Engineering: Hazard Analysis
Name of Student
Institutional Affiliation

MECHANICAL ENGINEERING: HAZARD ANALYSIS 2
FIGURE 3 is the cause tree for this TOP event, showing the conventional 'AND' and 'OR' gates
together with typical fail-to-danger fault frequencies for the control and alarm equipment,
including estimates for electricity and instrument air failure. Also shown are probabilities (3%)
for operator failure to respond to the alarm system which is rated at 97% reliable.
a) Complete the conversion of this cause tree into a FAULT tree, allowing for testing the
alarm system once per week. (Use the simple fractional dead time formula.)
The hazard analysis mainly indicated as follows
Fault tree analysis mainly defined as the deductive and top-down evaluation of failure which
tends to results to a system with the makeable undesired state. The evaluation mainly grounded
on the Boolean logic which combines the lower-level events series. This analysis mainly
incorporates the application of the reliability as well as safety engineering with the aim of

MECHANICAL ENGINEERING: HAZARD ANALYSIS 3
ensuring that one understands the occurrences of the failures in the system decisively. For this
evaluation the occurrence of the overall norm mainly illustrated as indicated in the analysis
below
b) State which pieces of equipment have the greatest effect on the top event frequency.
From the observation that some amount of hydrogen gas is enclosed somewhere in the chambers
closer to the regions that Welder had initiated his work, it can be inferred that an explosion if fire
may erupt. Consequently, a possibility that the worker alongside his gear might also be on fire is
also noted. From this understanding, there must be some emergency measures put in place to
prevent further damages. These include alarms, a swift and immediate use of fire extinguishers,
making the sections free from anything and making available an ambulance or medical van to the
victims. All measures should be taken into account in order to bridge any gap and negligence
from the maintenance personnel (Yuan, Cui, Tao, & Ma, 2018).

MECHANICAL ENGINEERING: HAZARD ANALYSIS 4
of workers while at the work area. Lastly the concern of do’s and don’ts while on the site should
be carefully taken care of in the long run.
c) If the reliability of the level detector and controller can be improved from a fault
frequency of 2.36 and 1.64 respectively to 0.5 per year, determine the new top event
frequency.
Quantitative analysis in line with the fault tree illustration provides one with the viable
opportunity on how to determine the emerging critical events in regard to the top event. The
analysis also stipulates that the resultant norm must be beneficial in the long run. In essence, it
helps in determining the probability as well as frequencies in line with the Prime events and
occurrences in the long run. there are two main methods used in the determination of the
quantitative in the analysis. The two methods are the cut sets and the working up tree. Preferably,
each procedure tends to have both the disadvantages and the advantages in line with the
individual analysis (Munk et al. 2018, June). The first method mainly applies in the computation of
the individual gate turns. The analysis mainly grounded on aspects such as the no power charger
or low probabilities. Thus, the analysis operates on the principles of the instantaneous
probabilities of the makeable faulty transformer of item 4. However the items used in the
process should be independent . the evaluations has to be repeated often until the viable value is
gathered as the Top event in the long run.
On the other hand, the second method encompasses on the identification of all the cut sets in
ensuring that the lead TOP event is obtained in the run. The evaluation mainly carried out for
each of the event and the summation of the results documented in the long run. The method has
the advantages in that it leads to the obtaining of the dependent failures. Conversely, it is

MECHANICAL ENGINEERING: HAZARD ANALYSIS 5
important to note that considerations should be incorporated since the summation of the
independencies often obtained prior (Mhenni, Nguyen, & Choley, 2018).
Given that
Frequencies are 2.36, 1.64, and 0.5
Also, probability for the OR-gate and the AND-gate mainly given with the below expressions
(Jankovsky, Denman, & Aldemir, 2018).
On the other hand, the Reliability calculations mainly given based on the illustration below
Thus, the power supply failure mainly expressed in line with the below analysis (Bethea, 2018).
The reliability computation mainly illustrated as follows (Wang, Chen, Wang, & Ye, 2018).

MECHANICAL ENGINEERING: HAZARD ANALYSIS 6
Probability for the top event given as
(A+B). [C.E + D.E + C.C + D.C + D.E)
OR-gate A= (0.6+0.04+2.36) = 3
OR-gate B=(0.97 x 0.03) = 0.029
(A.B) = (3 x 0.029) = 0.0873
OR-gate C= [1.64 + 0.05 + 0.07+0.6]
= 2.36
The combination of the OR gate and the AND-gate at
= [0.0873 x 2.36]
= 0.206028
The new event is given as
Probability = (1−0.206028)
= 0.793972
Conclusion

MECHANICAL ENGINEERING: HAZARD ANALYSIS 7
In summary, the paper discussed the hazard analysis in the mechanical engineering via the
application of the Fault tree analysis and Boolean logic system. The analysis also incorporated
the calculation of the probability and the top event in line with OR-gate and AND-gate.

MECHANICAL ENGINEERING: HAZARD ANALYSIS 8
References
Bethea, R. M. (2018). Statistical methods for engineers and scientists. Routledge.
Jankovsky, Z. K., Denman, M. R., & Aldemir, T. (2018). Dynamic event tree analysis with the
SAS4A/SASSYS-1 safety analysis code. Annals of Nuclear Energy, 115, 55-72.
Mhenni, F., Nguyen, N., & Choley, J. Y. (2018). SafeSysE: A safety analysis integration in
systems engineering approach. IEEE Systems Journal, 12(1), 161-172.
Munk, P., Abele, A., Thaden, E., Nordmann, A., Amarnath, R., Schweizer, M., & Burton, S.
(2018, June). Semi-automatic safety analysis and optimization. In 2018 55th
ACM/ESDA/IEEE Design Automation Conference (DAC) (pp. 1-6). IEEE.
Wang, T., Chen, J., Wang, C., & Ye, X. (2018). Understand e-bicyclist safety in China: Crash
severity modeling using a generalized ordered logit model. Advances in Mechanical
Engineering, 10(6), 1687814018781625.
Yuan, C., Cui, H., Tao, B., & Ma, S. (2018). Cause factors in emergency process of fire accident
for oil–gas storage and transportation based on fault tree analysis and modified Bayesian
network model. Energy & Environment, 0958305X18760222.

MECHANICAL ENGINEERING: HAZARD ANALYSIS 9
References