Engineering composites are often GRPR and CRPR, with the PR standing for | 英语复习选择题

单选题 A creep resistant material should have

A、 a high elastic modulus.

B、 a high melting temperature.

C、 a high yield strength.

D、 a long fatigue life.

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单选题 A material has a melting point of 200 degrees Celsius, and we apply constant force loads at 20 degrees Celsius.

A、 We do not expect creep deformation to occur.

B、 Fast fracture should occur before creep deformation begins.

C、 We do expect creep deformation to occur.

D、 We do not have enough information to predict creep deformation.

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单选题 A“stiff”material has a relatively high value of

A、 elastic modulus.

B、 Poisson’s ratio.

C、 yield stress.

D、 tensile strength.

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单选题 A“critical crack length”is associated with

A、 plastic yielding

B、 creep permanent strain.

C、 fast fracture.

D、 non-protective oxide films.

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单选题 A“ductile”material has a relatively high value of

A、 percent elongation.

B、 hardness.

C、 elastic modulus.

D、 ultimate tensile strength.

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单选题 Charpy and Izod are names associated with equipment used to measure

A、 hardness.

B、 yield strength.

C、 creep resistance.

D、 toughness.

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单选题 A“strong”material has a relatively high value of

A、 shear modulus.

B、 yield stress.

C、 percent elongation.

D、 creep rate.

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单选题 Creep deformation failure is a concern

A、 in jet engines.

B、 in automobile engines.

C、 with aircraft wings.

D、 with plastics at low temperatures.

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