MECH 4013 Lab 1 Stress Shielding

need help with this review part A engineering of materials

Flag question You have been given the following test sample data following mechanical testing of 15 test pieces of a modified Alumina. What is the Weibull modulus of this material? Would you advise the use of this material over one with a Weibull Modulus of 19.6 and a mean failure stress of 270 MPa, if you anticipate that the peak stress on the material could be 255 MPa? Sample 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Select one or more: Failure Stress (MPa) 297 293 270 300 260 286 265 295 4 293 280 288 263 290 298 275

1. Which ASTM Testing Standards define the testing methodology for impact testing of: a. Metallic Materials b. Plastic Materials 2. Describe the difference between Ductile and Brittle Fracture in polycrystalline materials

You are called as an expert witness to analyze the fracture of a sintered silicon carbide plate that was fractured in bending when a blunt load was applied to the plate center. Measurement of the distance between the fracture origin and the mirror/mist boundary on the fracture surface gives a radius of 0.796 mm. You are given three pieces of the same SiC to test, and you determine that the mirror radius is 0.603, 0.203, and 0.162 mm for bending failure stress levels of 225, 368, and 442 MPa, respectively. What is your estimate of the stress present at the time of fracture for the original plate?

3. A structural component is made from a steel alloy with a plain strain fracture toughness of 77.0 MPa √m and a yield strength of 1400 MPa. The dimensions of the component allow it to be modeled as a wide plate. (a) If the design stress is half of the yield strength and Y =1, determine the critical flaw size, a. (b) If the flaw size resolution limit of the flaw detection equipment is 4mm, determine if a critical flaw can be detected. Consider both an internal flaw and a surface flaw.

QUESTION 18 A chemicals company is looking to optimise the materials selection for their synthesis vessel with safety being the key priority. The tank can be treated as a small thin-walled spherical pressure vessel and the engineers are considering a 'yield before break' design concept. Given that a crack of length will propagate by fast fracture when the stress intensity factor reaches the fracture toughness of the material select the correct materials property index relevant to this design criterion. Fracture toughness K₁=Y₁₁√√ IC O M= O M= OM= OM= O M= OM= K f P K 2 IC K IC 6 f 6 P K f IC σα y K IC 2 f IC

QUESTION 18 A chemicals company is looking to optimise the materials selection for their synthesis vessel with safety being the key priority. The tank can be treated as a small thin-walled spherical pressure vessel and the engineers are considering a 'yield before break' design concept. Given that a crack of length will propagate by fast fracture when the stress intensity factor reaches the fracture toughness of the material select the correct materials property index relevant to this design criterion. Fracture toughness K₁=Y₁₁√√ IC O M= O M= O M= COM: = O M= O M= K 6 6 P K IC K K IC P σα y 6 IC K IC 2 f IC 2

Stuck need help! Problem is attached. please view attachment before answering.  Really struggling with this concept. Please show all work so I can better understand ! Thank you so much.

Question 4 Figure 3 shows the impact of temperature and stress on mechanical properties of materials (a) 1200 High temperature or high stress (b) 900 Medium temperature or medium stress Brittle Ductile Low temperature or low stress 600 300 +Transition temperature -80 -40 40 80 Time Temperature (°C) Figure 3 (a) Izod impact test results for nylon thermoplastic polymer. (b) Creep test results Using Figure 3, explain: (a) The dependence of failure modes on temperature. (b) The effect of temperature changes and stress on the creep rate. Impact strength (J/m) Strain

How does the field of mechanical engineering contribute to advancements in renewable energy technologies and sustainable solutions?

Table 1: Mechanical behavior of human cadaver tibial bones during pure torsional loads applied with the proximal tibia fixed and the torque applied to the distal tibia until there is bone fracture. Medial condyle Tibial tuberosity- Medial malleolus -Lateral condyle Head of fibula Ti-6Al-4V grade 5 Stainless Steel 316L Region of bone resection -Lateral malleolus L = 365 mm Annealed Annealed Torque at ultimate failure (bone fracture) Displacement (twist angle) at ultimate failure Torsional Stiffness Table 2: Mechanical properties of candidate materials for the rod. Material Process Yield Strength (MPa) 880 220-270 Do = 23 mm Elastic Modulus (GPa) 115 190 d₁ = 14 mm Figure 1: Representative tibia bone showing the resection region (blue arrows) and median length (L). A circular cross section of distal tibia taken at the level of resection) showing the median inner (di) and outer (Do) diameters of the cortical bone. A tibia bone after resection with the proposed metal solid rod (black line)…

Calculate the impacts on size (diameter) and mass/unit length of replacing a natural bone in the leg with one made of steel, aluminum, or titanium. Use compressive strengths and densities provided in class for bone, steel, and aluminum. Use r=0.00443 kg/cm3, and s=848 MPa for titanium. Assume the bone is hollow with outside diameter 2.5 cm and inside diameter 3 cm. Maintain the same inside diameter. HINT: first calculate the load on the bone..

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You have been asked to draw up a specification for a ceramic cladding tile that is likely to experience tensile stresses of 89 MPa during its installation and service lifetime. If the ceramic has a specific surface energy of 0.35 J/m2 and its Youngs Modulus is 85 GPa what would be the maximum length of an internal flaw that would not result in fracture of the tile? (This question has only one correct answer) a. 2.53 µm b. 5.06 µm c. 4.78 μm d. 2.53 mm e. 2.39 mm f. 4.78 mm g. 2.39 um

Which of the following statements is incorrect for polymers? (This question has only one correct answer) а. The fatigue behavior of polymers is more sensitive to loading frequency than for metals Ob. Amorphous and semi-crystalline polymers both have lower strength than crystalline polymers О с. Strength increases at higher temperatures as the material softens O d. It is desirable to have a ductile-to-brittle transition temperature below room temperature

QUESTION 1 Select from the following statements, those which describe the process and conditions required for brittle fracture. (Note: Partial credit is not available for this question. Credit will only be awarded if all correct answers, and no incorrect answers, are selected). A. Occurs along defined crystallographic planes, thus leaving smooth fracture surfaces B. Occurs due to repeated loading and unloading below the yield strength of the material OC. Occurs in materials where the bonding strength is high relative to the yield strength D. The stress concentration at the crack tip exceeds the inter-atomic bonding energy ☐ E. Involves the nucleation, growth and coalescence of voids, thus resulting in rough fracture surfaces OF. Is a slow process whereby there is warning prior to failure

A fracture surface of a metal matrix composite (nickel with silicon carbide fibres) is investigated with a Scanning Electron Microscope (SEM). Questions: a. Which signals can you use to make an image of the sample? b. Which signal do you prefer to observe the fracture surface? c. How can you discriminate between the matrix and the fibres? d. How can you increase the magnification to observe a detail with the SEM?

FRACTURE TOUGHNESS

1. Glass and epoxy have stiffnesses of Eglass = 70 GPa and Eepoxy = 3.5 GPa and fracture toughness values of Kic-glass = KIC-epoxy = 1 MPa√m. a. Which has a higher toughness (GC)? b. What might the broken surfaces look like after failure, and how does that relate to the energy dissipated during fracture?