enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Niobium–tin - Wikipedia

    en.wikipedia.org/wiki/Niobium–tin

    Commercial superconductors manufactured by the bronze process generally have a pre-strain value around 0.2% to 0.4%. The so-called strain effect causes a reduction in the superconducting properties of many materials including niobium tin. The critical strain, the maximum allowable strain over which superconductivity is lost, is given by the formula

  3. Portevin–Le Chatelier effect - Wikipedia

    en.wikipedia.org/wiki/Portevin–Le_Chatelier_effect

    This effect also can appear on the specimen's surface and in bands of plastic deformation. This process starts at a so-called critical strain, which is the minimum strain needed for the onset of the serrations in the stress–strain curve. The critical strain is both temperature and strain rate dependent. [2] The existence of a critical strain ...

  4. Theoretical strength of a solid - Wikipedia

    en.wikipedia.org/wiki/Theoretical_strength_of_a...

    When a solid is in tension, its atomic bonds stretch, elastically. Once a critical strain is reached, all the atomic bonds on the fracture plane rupture and the material fails mechanically. The stress at which the solid fractures is the theoretical strength, often denoted as . After fracture, the stretched atomic bonds return to their initial ...

  5. Material failure theory - Wikipedia

    en.wikipedia.org/wiki/Material_failure_theory

    The fracture toughness and the critical strain energy release rate for plane stress are related by = where is the Young's modulus. If an initial crack size is known, then a critical stress can be determined using the strain energy release rate criterion.

  6. Dynamic recrystallization - Wikipedia

    en.wikipedia.org/wiki/Dynamic_recrystallization

    The new grains are less strained, causing a decrease in the hardening of a material. Dynamic recrystallization allows for new grain sizes and orientation, which can prevent crack propagation. Rather than strain causing the material to fracture, strain can initiate the growth of a new grain, consuming atoms from neighboring pre-existing grains.

  7. Critical resolved shear stress - Wikipedia

    en.wikipedia.org/wiki/Critical_resolved_shear_stress

    The figure also shows the effect of increased strain rate generally increasing the critical resolved shear stress for a constant temperature as this increases the dislocation density in the material. Note that for intermediate temperatures, i.e. region II, there is a region where the strain rate has no effect on the stress.

  8. Critical plane analysis - Wikipedia

    en.wikipedia.org/wiki/Critical_plane_analysis

    The chief advantage of critical plane analysis over earlier approaches like Sines rule, or like correlation against maximum principal stress or strain energy density, is the ability to account for damage on specific material planes. This means that cases involving multiple out-of-phase load inputs, or crack closure can be treated with high ...

  9. J-integral - Wikipedia

    en.wikipedia.org/wiki/J-integral

    The J-integral represents a way to calculate the strain energy release rate, or work per unit fracture surface area, in a material. [1] The theoretical concept of J-integral was developed in 1967 by G. P. Cherepanov [2] and independently in 1968 by James R. Rice, [3] who showed that an energetic contour path integral (called J) was independent of the path around a crack.