Mechanical testing — choose the primary material type for compression testing: Compression tests are typically performed on which class of materials?
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Aductile
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Bbrittle
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Cmalleable
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Dplastic
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Eelastomeric
Answer
Correct Answer: brittle
Explanation
Introduction:Compression and tension tests reveal different failure behaviors. Understanding which materials are best assessed in compression is key to proper characterization.Given Data / Assumptions:
- Room-temperature, quasistatic tests.
- Standard specimen geometries.
Concept / Approach:Brittle materials (e.g., cast iron, concrete, stone, ceramics) have low tensile ductility and often fail suddenly in tension. Their compressive strength can be significantly higher and measured reliably without the complications of necking that ductile materials exhibit in tension.Step-by-Step Solution:
Identify class with limited tensile strain capacity: brittleSelect compression as suitable to avoid tensile cracking and to obtain meaningful strengthChoose “brittle” as the material category primarily tested in compressionVerification / Alternative check:Concrete testing protocols (e.g., cube or cylinder compressive tests) exemplify the practice of evaluating brittle materials in compression as a standard index of quality.Why Other Options Are Wrong:
- Ductile/malleable/plastic: Commonly characterized via tension yielding and elongation; compression may cause barreling and friction effects.
- Elastomeric: Characterized by large elastic deformations and different test setups.
Common Pitfalls:Assuming all materials are best characterized in tension; specimen-end friction and barreling must be controlled in compression tests.Final Answer:
brittle