What is notch sensitivity factor?
The notch sensitivity of a material is a measure of how sensitive a material is to notches or geometric discontinuities. Notch sensitivity is influenced by many parameters such as notch geometry. Three types of notch geometries, V-shape, U-shape and -shape notches of various sizes are considered in this investigation.
What is notch sensitivity and stress concentration factor how they are calculated?
Maximum stress determination will require you to first calculate the stress concentration factor, Kt, that accounts for the reduction of cross- sectional area, and the notch sensitivity, q. q = (Kf –1)/(Kt-1). Generally, q is between 0 and 1. If q is zero, then Kf =1 and the material is not sensitive to notches at all.
What is notch sensitivity in machine design?
3. Lukas P, Kunz L and Svoboda M, Fatigue notch sensitivity of ultrafine-grained copper, Materials Science and Engineering A, 391 (2005) 337. Article Google Scholar. 4. Zheng X L, Wang H, Yan J H, Notch strength and notch sensitivity of polymethyl methacrylate glasses, Materials Science and Engineering A, 349 (2003) 80 …
How do you find the fatigue notch factor?
The stress concentration factor Kt = 2.65 determined by finite element analysis gives the fatigue notch factor Kf = 2.20 (or Kf max = 2.50) in the case of A-36 mild steel (with a* = 0.025 mm, see Fig. 4.2).
What is a notch radius?
Description. The radial notch is a narrow, oblong, articular depression on the lateral side of the coronoid process; it receives the circumferential articular surface of the head of the radius.
What is the importance of stress concentration factor?
A stress concentration factor (Kt) is a dimensionless factor that is used to quantify how concentrated the stress is in a mechanical part. It is defined as the ratio of the highest stress in the part compared to a reference stress.
What does low notch sensitivity mean?
By definition, Notch Sensitivity is the sensitivity of the material to the developing notches Under cyclic/fluctuating loading due to the stress concentration, geometric discontinuity, and it also depends on the hardness of the material.
What is the notch effect?
What is the notch effect and how does it affect bolts? A notch is basically each change of the cross-section of a component. It may come from drill holes, grooves or cross-sectional variations. Notches result in uneven stress distribution, leading to stress peaks – known as the notch effect.
What is fatigue notch factor?
The ratio of the fatigue strength of an unnotched specimen to the fatigue strength of a notched specimen of the same material and condition; both strengths are determined at the same number of stress cycles.
What is the maximum stress concentration factor?
A stress concentration factor is the ratio of the highest stress (smax)) to a reference stress (s) of the gross cross-section. As the radius of curvature approaches zero, the maximum stress approaches infinity. Note that the stress concentration factor is a function of the geometry of a crack, and not of its size.
Can stress concentration factor be less than 1?
Basic stress analysis calculations assume that parts are smooth, have a uniform cross-section, and have no irregularities. If the material is flawless with no discontinuities, then the stress concentration factor is 1. If there is a discontinuity, then the stress concentration factor is greater than 1.
How to find out the notch sensitivity?
So how we can find out the notch sensitivity. well, we have a formula that. K f = Fatigue stress concentration factor. K t = Theoretical stress concentration factor. We have discussed the notch sensitivity and how it is different from the other notch which is given for reducing the stress concentration.
What is the notch sensitivity for stress raisers?
The value of the notch sensitivity for stress raisers with a significant linear dimension (e.g. fillet radius) R and a material constant ” a ” is given by: (10.33)q = 1 (1 + a R) Typically, a = 0.01 for annealed or normalised steel, 0.0025 for quenched and tempered steel and 0.02 for aluminium alloy.
How to calculate fatigue notch factors for a notched shaft?
The fatigue notch factors for a notched shaft under axial, bending, shear, and torsional stress (K ax,f,K b,f,K s,f,K t,f) can be calculated from the corresponding elastic stress concentration factors (K ax,t,K b,t,K s,t,K t,t) and the K t/K f ratios (n K,σ(r), n K,σ(d), n K,τ(r), n K,τ(d)) as follows:
What is the elastic fatigue notch factor KF?
The ‘elastic’ fatigue notch factor Kf is the essential parameter which defines the fatigue-effective stresses within the notch stress approach (see eq. (4.1) ).