PE Mechanical Engineering Machine
Design And Materials Exam With Correct
Questions And Answers 2024
Thermal .Strain .- .correct .answer.Change .in .dimensions .due .to .a .change .in .temperature
Specific .heat .(or .heat .capacity) .- .correct .answer.The .amount .of .heat .required .to .raise .the
.temperature .of .a .material .or .an .amount .of .material .by .1 .degree.
Elements .of .Machine .Design .Methodologies .- .correct .answer.1. .Identifying .Requirements
2. .Risk .assessment
3. .Verification .and .validation
Examples .of .Requirements .(for .machine .design) .- .correct .answer.Functional
.performance
Limites .on .size
User .interfaces
External .interfaces
Production .volume
Costs
Available .materials
Available .porduction .technologies
Foreseeable .usage .conditions
Foreseeable .environmental .conditions
Foreseeable .misuse
Required .safety .factors
Life .cycle .duration
product .retirement
Risk .Assessment .Methodologies .- .correct .answer.Hierarchy .of .controls .for .addressing
.hazards
Fault .Tree .Analysis .(FTA)
Failure .Modes .and .Effects .Analysis .(FMEA)
Hierarchy .of .Controls .for .Addressing .Hazards .- .correct .answer.1. .Eliminate .or .substitute:
.design .to .avoid .hazard, .or .redesign .to .eliminate .hazard
,2. .Engineering .controls: .Limit .access .to .the .hazard .through .guards .and .barriers
3. .Administrative .controls: .Attempt .to .alert .personnel .to .the .presence .of .hazard .through
.alarms, .warnings, .labels, .instructions, .work .practices, .training
4. .Personal .protective .equipment .(PPI): .personnel .must .utilize .protective .gear .because
.exposure .to .the .hazard .cannot .be .reliably .avoided
Fault .Tree .Analysis .(FTA) .- .correct .answer.A .top-down, .logic-based .methodology .for
.analyzing .a .system .failure .condition .and .determining .the .contributing .lower-level .events.
.Steps .include:
.i. .Identify .the .system .failure .condition .of .interest.
.ii. .Identify .faults .that .could .lead .to .the .system .failure .condition.
.iii. .Identify .all .known .causes .that .could .lead .to .the .identified .faults.
.iv. .Connect .causes, .and .link .faults .to .causes, .through .Boolean .logic .gates .AND .and .OR.
.v. .Group .common .fault .causes .and .refine .logical .connections.
.vi. .Identify .countermeasures .to .address .fault .causes.
Failure .Modes .and .Effects .Analysis .(FMEA) .- .correct .answer.A .risk .analysis .methodology
.to .evaluate .product/system .components .(or .functions) .for .the .following:
.i. .Potential .failure .modes
.ii. .Effects .of .the .failure
.iii. .Severity .of .the .failure .effects
.iv. .Cause(s) .of .the .failure
.v. .Likelihood .that .a .specific .cause .will .occur
.vi. .Likelihood .that .design .controls .(such .as .validation/verification) .will .prevent .the
.occurrence .(or .reduce .the .rate .of .occurrence) .of .the .cause/failure, .or .detect .the
.cause/failure .before .the .product/system .is .released .to .the .customer
Verification .- .correct .answer.Analysis .of .whether .a .product/system .complies .with .codes,
.regulations, .standards, .specifications, .or .imposed .conditions:
.i. .Testing .to .requirements .in .codes, .regulations, .and .standards
.ii. .Evaluation .of .whether .product/system .was .installed .in .accordance .with .controlling
.documents .pertaining .to .the .design, .installation, .operation, .and .performance .of .the
.product/system
Validation .- .correct .answer.Analysis .of .whether .a .product/system .meets .the .expectations
.of .customers, .end .users, .or .external .entities
.i. .Usability .studies
.ii. .Prototyping
.iii. .Evaluation .of .whether .specifications .are .sufficient .to .create .a .product/system .that
.meets .customer .expectations
Close .Sliding .Fits .- .correct .answer.RC1, .Running .Clearance .Fit
Intended .for .the .accurate .location .of .parts .that .must .assemble .without .perceptible .play
Sliding .Fits .- .correct .answer.RC2, .Running .Clearance .Fit
Intended .for .accurate .location, .but .with .greater .maximum .clearance .than .RC1.
,Parts .made .to .this .fit .move .and .turn .easily .but .are .not .intended .to .run .freely, .and .in .the
.larger .sizes .may .seize .with .small .temperature .changes.
Precision .Running .Fits .- .correct .answer.RC3, .Running .Clearance .Fit
Precision .running .fits .are .about .the .closest .fits .that .can .be .expected .to .run .freely, .and .are
.intended .for .precision .work .at .slow .speeds .and .light .journal .pressures, .but .are .not
.suitable .where .appreciable .temperature .differences .are .likely .to .be .encountered.
Close .Running .Fits .- .correct .answer.RC4, .Running .Clearance .Fit
Close .running .fits .are .intended .chiefly .for .running .fits .on .accurate .machinery .with
.moderate .surface .speeds .and .journal .pressures, .where .accurate .location .and .minimum
.play .are .desired.
Medium .Running .Fits .- .correct .answer.RC5, .RC6, .Running .Clearance .Fit
Medium .running .fits .are .intended .for .higher .running .speeds, .or .heavy .journal .pressures,
.or .both.
Free .Running .Fits .- .correct .answer.RC7, .Running .Clearance .Fit
Free .running .fits .are .intended .for .use .where .accuracy .is .not .essential, .or .where .large
.temperature .variations .are .likely .to .be .encountered, .or .under .both .these .conditions.
Loose .Running .fits .- .correct .answer.RC8, .RC9, .Running .Clearance .Fit
Loose .running .fits .are .intended .for .use .where .wide .commercial .tolerances .may .be
.necessary, .together .with .an .allowance, .on .the .external .member.
Light .Drive .Fits .- .correct .answer.FN1, .Force .or .Shrink .Fit
Light .drive .fits .are .those .requiring .light .assembly .pressures, .and .produce .more .or .less
.permanent .assemblies.
Medium .Drive .Fits .- .correct .answer.FN2, .Force .or .Shrink .Fit
Medium .drive .fits .are .suitable .for .ordinary .steel .parts, .or .for .shrink .fits .on .light .sections.
Heavy .Drive .Fits .- .correct .answer.FN13 .Force .or .Shrink .Fit
Heavy .drive .fits .are .suitable .for .heavier .steel .parts, .or .for .shrink .fits .in .medium .sections.
Force .Fits .- .correct .answer.FN4, .FN5, .Force .or .Shrink .Fit
Force .fits .are .suitable .for .parts .that .can .be .highly .stressed, .or .for .shrink .fits .where .the
.heavy .pressing .forces .required .are .impractical
Locational .Clearance .Fits .- .correct .answer.LC, .Locational .Fit
Locational .clearance .fits .are .intended .for .parts .which .are .normally .stationary, .but .that .can
.be .freely .assembled .or .disassembled.
Locational .Transition .Fits .- .correct .answer.LT, .Locational .Fit
, Locational .transition .fits .are .a .compromise .between .clearance .and .interference .fits, .for
.applications .where .accuracy .of .location .is .important, .but .either .a .small .amount .of
.clearance .or .interference .is .permissible.
Locational .Interference .Fits .- .correct .answer.LN, .Locational .Fit
Locational .interference .fits .are .used .where .accuracy .of .location .is .of .prime .importance,
.and .for .parts .requiring .rigidity .and .alignment .with .no .special .requirements .for .bore
.pressure.
Arithmetic .Mean .- .correct .answer.f .X1, .X2...Xn .represents .the .values .of .a .random .sample
.of .n .items, .the .mean .of .these .items .(Xbar) .is .the .sum .of .the .items .divided .by .the .number
.of .items
Weighted .Arithmetic .Mean .- .correct .answer.Xbar_w .= .sum(weight_i .* .Xi) ./ .sum(weight_i)
Variance .- .correct .answer.The .variance .of .the .population .is .the .arithmetic .mean .of .the
.squared .deviations .from .the .population .mean
Standard .Deviation .- .correct .answer.Square .root .of .the .population .variance
Sample .Variance .- .correct .answer.The .sum .of .the .squared .deviations .from .the .sample
.mean .divided .by .n-1
Sample .Standard .Deviation .- .correct .answer.Square .root .of .the .sample .variance
Median .- .correct .answer.The ."middle" .value .of .the .sample
When .the .discrete .data .is .rearranged .in .increasing .order .AND .n .is .odd, .the .median .is .the
.value .of .the .(n+1)/2 .items
When .n .is .even, .the .median .is .the .average .of .the .(n/2) .and .(n/2 .+ .1) .items
Mode .- .correct .answer.The .value .that .occurs .most .frequently .in .a .given .data .set.
Sample .range .(R) .- .correct .answer.The .largest .sample .value .minus .the .smallest .sample
.value
Confidence .Level .- .correct .answer.The .probability .that .the .value .of .the .parameter .falls
.within .a .specified .range .of .values
Uncertainty .- .correct .answer.Let .wR .be .the .uncertainty .in .the .result .and .w1,w2...wn .be
.the .uncertainties .in .the .independent .variables.
The .uncertainty .of .the .equation .is .the .square .root .of .the .sum .of .the .squares .of .each
.uncertainty .multiplied .by .the .derivate .of .the .equation .with .respect .to .the .variable
.assoicated .with .the .uncertainty.
Tests .for .out .of .control .(for .3-sigma .control .limits) .- .correct .answer.1. .A .single .point .falls
.outside .the .control .limits.
