lab 3

define stress

Stress is the internal resistance of a material to deformation, quantified as force per unit area (N/m²), crucial for understanding material behavior under loads.

define strain

Strain quantifies deformation in a material, expressed as the ratio of change in length to original length, indicating how much a material stretches or compresses.

define yield strength

Yield strength is the stress threshold at which a material begins to deform plastically, meaning it will not return to its original shape when the load is removed.

define ultimate tensile strength

Ultimate tensile strength (UTS) represents the maximum stress a material can endure while being stretched before failure occurs.

define young’s modulus

Young's modulus is a measure of material stiffness, defined as the ratio of tensile stress to tensile strain in the elastic range, indicating how much it will deform under applied force.

define ductility

Ductility is the ability of a material to undergo significant plastic deformation before fracture, often measured by its elongation and reduction in area during tensile testing.

how does carbon steel effect microstructure

Carbon content affects steel's microstructure, influencing phases such as pearlite and ferrite, which consequently change its hardness, strength, and ductility.

how does carbon steel effect tensile properties

Higher carbon content in carbon steels enhances tensile strength and hardness but reduces ductility, affecting performance under tensile stress.

how is austenitic stainless steel’s microstructure different from carbon steel’s

Austenitic stainless steel has a face-centered cubic (FCC) structure that enhances ductility and corrosion resistance, contrasting with carbon steel's body-centered cubic (BCC) structure.

how are austenitic stainless steel’s tensile properties different from carbon steel’s

Austenitic stainless steel typically displays greater ductility and toughness along with good corrosion resistance, whereas carbon steel usually has higher yield strength but lower ductility.

define a ductile failure

A ductile failure is characterized by extensive plastic deformation before fracture, often seen with visible necking that indicates an impending break.

define a brittle failure

A brittle failure occurs with minimal plastic deformation, leading to sudden material fracture without prior warning, typical of hard, brittle materials.

define ASTM standard E8, what are its key parameters

ASTM Standard E8 outlines procedures for tensile testing of metallic materials, emphasizing specimen preparation methods, test speed, and strain measurement techniques.

how do you calculate 0.2% offset yield strength

The 0.2% offset yield strength is calculated by drawing a line parallel to the initial linear portion of the stress-strain curve, offset by 0.2% strain, and determining the stress at which it intersects the curve.

how do you calculate ultimate tensile strength

Ultimate tensile strength is derived from the stress-strain curve by identifying the peak stress point just before material failure.

how do you calculate % elongation

Percentage elongation is calculated using the formula: ((final length - original length) / original length) x 100, representing the ability of a material to stretch before failing.

how do you calculate young’s modulus

Young's modulus is calculated by determining the slope of the linear section of the stress-strain curve, representing the relationship between stress and strain.

what is looked for for fracture characterization

Fracture characterization involves analyzing surface features, fracture modes (ductile or brittle), and microstructural details to understand failure mechanisms.

what was the tensile behavior of the 1008 steel

1008 steel generally demonstrates good ductility with moderate tensile strength, allowing for significant elongation before failure occurs.

what was the tensile behavior for the 1095 steel

1095 steel exhibits high tensile strength but lower ductility, often leading to brittle failure under specific conditions.

what was the tensile behavior for the 304 stainless steel

304 stainless steel provides excellent ductility and corrosion resistance, along with adequate tensile strength for diverse applications.

compare the modulus of elasticity for 1018 steel, 1095 steel, and stainless steel

1018 steel and 1095 steel exhibit similar modulus of elasticity values, whereas stainless steel shows slightly lower values, indicating differences in material stiffness.

compare the strength of 1018 steel and 304 stainless steel

1018 steel has lower tensile strength than 304 stainless steel, which benefits from alloying elements that enhance its strength and toughness.

compare the elongation of 1018 steel and 304 stainless steel

304 stainless steel typically showcases greater elongation compared to 1018 steel, reflecting its superior ductility.

how do you calculate young’s modulus using cross-head displacement

Young's modulus from cross-head displacement is determined by dividing the applied load by the corresponding displacement, considering values in the elastic region.

how do you calculate young’s modulus using extensometer data

Using extensometer data, Young's modulus is calculated by taking the load and measuring elongation within the elastic response of the material.

why are the young’s modulus different when calculated through cross-head displacement vs from extensometer data, and which is more accurate

Differences arise from measurement methods; extensometer data is considered more accurate due to localized strain measurements, compared to cross-head displacement.

how do you calculate yield strength using cross-head displacement

Yield strength from cross-head displacement is identified by detecting the stress value at which permanent deformation initiates on the stress-strain curve.

how do you calculate yield strength using extensometer data

Yield strength calculated using extensometer data is determined at the stress level corresponding to the onset of permanent deformation on the stress-strain curve.

why are the yield strengths different when calculated through cross-head displacement vs from extensometer data, and which is more accurate

Yield strength discrepancies arise from measurement precision; extensometer data generally provides more accurate values due to better local strain capture