Question 1 The actual strength of CERAMIC crystals is usually much lower than its theoretical strength because of the presence of: Point defects Dislocations Pores and micro-cracks None of the above Question 2 According to Griffith failure criterion, the actual failure strength of a ceramic component is decided by its Smallest flaw c Average flaw size None of the answers Largest flaw Question 3 The most common way to measure the failure strength of ceramic materials is: Bending test Compression test Shear test Tensile test Question 4 The Weibull modulus m is a figure of merit for the reproducibility or reliability of strength in a range of ceramic samples. Which understanding about m is WRONG? The larger the m, the more samples would fail below a certain stress o The larger the m, the less samples would fail below certain stress o If m=, there is a sharp cut-off stress above which all samples fail. If m = 0, the probability of sample survival is the same at all stresses. Question 5 The temperature-dependent mechanical behavior of a polymer is dependent on its All of these answers Degree of crystallinity g Amount of crosslinking Question 6 Increasing the degree of polymerization of a polymer does not always affect its Tg Crystallinity Melt viscosity Strength Question 7 Generally, the purpose to make a composite is to achieve: High toughness A unique combination of properties High stiffness High strength Question 8 The mechanical properties of composites are related to All of these answers Performance, content, and arrangement of the reinforcement. Combination and interface situation of the reinforcement and matrix Performance, content, and arrangement of the matrix. Question 9 With the same material composition and volume fraction, yields the highest tensile strength N direction in three directional fiber reinforced composite T direction in orthogonal fiber reinforced composite L direction in unidirectional fiber reinforced composite N direction in unidirectional fiber reinforced composite Question 10 Which understanding about the mechanical behavior of unidirectional fiber composites is WRONG? The strength of the composite reinforced with continuous fibers is simply the mean of the component values weighed according to their volume fraction The Rule of Mixture method is based on the weighted contributions from the fibers and the matrix Theoretically, the strength and stiffness of a composite can be predicted by the Rule of Mixture method. The strength of a composite is always greater than that of the matrix alone
