A single cylinder vertical engine has a bore of 300 mm and a stroke of400 mm. the connecting rod is 1 m long and the mass of reciprocating parts is 140 kg. On the expansion stroke, with the crank at 30o fromtop dead centre, the gas pressure is 0.7MPa. If the engine runs at 250rpm, determine (i) net force acting on the piston (ii) resultant load onthe gudgeon pin, (iii) thrust on the cylinder walls, and (iv) the speed above which, other things remaining the same, the gudgeon pin load would be reversed in direction.
The material (Cp = 460 J/kg°C, ? = 7600 kg/m3
) has initally
uniform temperature of 100 °C. The material has placed to a
convection environment (h = 100 W/m2
°C, T8 = 20 °C). The
material has a heat generation rate of 90e+3 kW/m3 while the
right face of the material is maintained to be 100 °C. Calculate
the temperature of the indicated nodes after 10 seconds.
ENGR7891 Fatigue and Fracture Analysis
Project 1: Fracture in Pressure Vessels
Due Date: Friday 04 Sep 2020
- This page must be attached to your project report as the front page.
- This project is to be conducted in groups assigned in the class.
- A single report is required from each group.
- The report must be saved as a PDF file and submitted together with its Turnitin
report via FLO.
- The similarity index in your Turnitin report should be less than 15%.
- Each student is required to participate in the entire project.
- The beginning of your report must identify each student’s contribution and ALL
students must print their name next to their stated contribution in the table.
- Students in a group will receive a mark based on their contribution percentage
specified in the table, unless otherwise discussed with the topic coordinator,
and agreed upon by all students in the group.
Complete the table below:
| Student Name | Student ID | Contribution (Give a Percentage) | Contribution (Give Details) | Date & Signature/Initials |
Project Description
Pressure vessels are wildly used in various industrial facilities to store pressurised gases or liquids. Due to the significant pressure levels, brittle fracture of pressure vessels can be dangerous resulting in catastrophic failures if a proper design and/or inspections/maintenance are not performed. This project aims to investigate fracture and fracture mechanics in pressure vessels through studying and reviewing the following aspects:
- An introduction to pressure vessels (definition, categorisation e.g. thin-walled, schematic figures with the main geometric parameters).
- Different types/shapes/configurations of pressure vessels.
- Typical ranges of pressures used in various industries/applications along with examples of pressurised gases and liquids stored in pressure vessels.
- Stress analysis (equations/formulations) for cylindrical and spherical vessels (thick- and thin-walled vessels).
- Common manufacturing methods/techniques used to construct pressure vessels.
- Common materials used for constructing pressure vessels.
- Important design parameters and well-known design codes/standards.
- Fracture in pressure vessels (include technical information)
- Examples of previous significant failures
- Prevention of brittle fracture in pressure vessels
- Leak-before-break design of pressure vessels (concept, formulation, etc)
Please note that:
- Your investigation can, of course, include some other relevant/useful aspects in addition to those suggested above.
- The last five aspects should be the main focus.
- Your report should not be less than 6,000 words (excluding references and figure captions).
- This is an engineering report, thus, your report should be strongly technical and scientific and should present in-depth details, figures (e.g. graphs, diagrams), tables, information, discussion, analysis/calculations.
- A proper referencing must be used.
- The report should have a proper structure with sections and subsections (if necessary) including Title, Names, Abstract, Body, Summary and References.
A vibrating system has the following constants: m = 17.5 kg,k = 70N/cm, and c = 0.70 N/cm/s.Determine (a) the damping factor ,(b) the natural frequency of damped oscillation (c) the loga-rithmic decrement,(d) the ratio of any two consecutive amplitudes.
Two plates are placed at a distance of 0.15mm apart. The lower plate is fixed while the upper plate having surface area 1.0 m2 is pulled at 0.3 nm/s. Find the force and power required to maintain this speed, if the fluid separating them is having viscosity 1.5 poise. (8) b) An oil film of thickness 1.5 mm is used for lubrication between a square plate of size 0.9m *0.9m and an inclined plane having an angle of inclination 200 . . The weight of square plate is 392.4 N and its slides down the plane with a uniform velocity of 0.2 m/s. find the dynamic viscosity of the oil.
A plane wall is placed to a room with a temperature of 39 ºC and the wall losesheat to the room by convection. An engineer covers the wall with 2.4 cm thickasbestos (k = 1.3 W/mK) material. The interface temperature of the wall andasbestos is measured to be 310 ºC. Determine the “h” (convection heat transfercoeff.) of the room if the maximum allowable outer surface (outer surface ofasbestos) temperature is 40 ºC.
Suppose you found a dial thermometer in a stockroom. Discuss several methods by which you might estimate random and systematic error in the thermometer? How would you estimate its uncertainty?
1 A hollow steel tube with an inside diameter of 80 mm must carry an axial tensile load of 330 kN. Determine the smallest allowable outside diameter of the tube if the working stress is 110 MN/m2:
The component of the previous exercise was made and tested. It failed in less than 105 cycles. A post-mortem revealed that it had fractured at the root of a threaded end, shown in (b) in the figure. The threads have a depth of 1.5 mm and a root radius of 0.2 mm. Given this additional information, how many cycles would you expect it to survive?
You are asked to select a polymer to make a flexible coupling. The polymer must have a modulus greater than 2 GPa. The objective is to maximize the available flexure without fracture. Use the chart of Figure 10.4 to identify two good choices to meet these requirements. Are there any metals that are as good?
Supersonic wind tunnels store air under high pressure in cylindrical pressure vessels—the pressure, when released, produces hypersonic rates of flow. The pressure vessels are routinely proof tested to ensure that they are safe. If such a cylinder, of diameter 400 mm and wall thickness 20 mm, made of a steel with a fracture toughness of 42 MPa.m1/2, survives a proof test to 40 MPa (400 atmospheres), what is the length of the largest crack it might contain?
Make a bar chart of mechanical loss coefficient, η. Low loss materials are used for vibrating systems where damping is to be minimized—bells, high-frequency relays and resonant systems. High loss materials are used when damping is desired—sound deadening cladding for buildings, cars and machinery, for instance. Use the chart to find:
(a) The metal with the lowest loss coefficient.
(b) The metal with the highest loss coefficient.
1. A material with a tensile stress σts 350 MPa is loaded cyclically about a mean stress of 70 MPa. If the stress range that will cause fatigue fracture in 105 cycles under zero mean stress is 60 MPa, what stress range about the mean of 70 MPa will give the same life?
2. A component made of the AISI 4340 steel with a tensile strength of 1800MPa and the S–N curve shown in Exercise E9.4 is loaded cyclically between 0 and 1200MPa. What is the R-value and the mean stress, σm? Use Goodman’s rule to find the equivalent stress amplitude for an R-value of 1, and read off the fatigue life from the S–N curve.