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Static and Dynamic Yield Stress: What's the difference and which should I use?The most commonly used method for obtaining a yield stress value is to shear the sample over a range of shear rates, plot the shear stress as a function of shear rate and fit a curve (various models are available) through the data points (see fig 1).
The intersection on the stress axis is then taken as the yield stress, the assumption being that any stress below this is insufficient to cause the sample to flow. Rheologists call this a dynamic yield stress; we are looking at the sample in motion (i.e. under shear) and extrapolating from this how it behaves when not in motion.
However, there's more than one way to skin a cat! Another approach is to start with the sample in its at-rest state (zero shear) and incrementally increase the stress until we identify at value at which it starts to flow i.e. we record non-zero shear rate (see fig 2)
We call this value a static yield stress - the stress at which we initiate flow - and it is usually considerably higher than its dynamic counterpart for any given product. In reality the sample is undergoing creep flow below this stress but we can assume for many practical purposes that it is static. This test can be performed with a quick (non-equilibrium) stress ramp on a controlled stress rheometer or a constant rate test on a vane-based tester.
So which yield stress should you use?
Well it depends on what you need to know. A good starting point is to match the test type to the flow process of interest: If you are interested in how a fluid stops flowing after shear (such as screen printing, dip coating, enrobing or slumping) then the dynamic yield stress is a key determinant. On the other hand if you are interested in how hard you need to push to get the fluid moving in the first place (spreadability of butters, texture of tubs of cream, mixer and pump start-up etc) then the product's static yield stress will prove a major factor.
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What is the ultimate shear strength of stainless steel 316 n 304 n 302?
It depends on how it is worked, but a minimum strength in tension is 80,000psi. In shear, it is 0.577 times the tension strength, or shear strength minimum = 46,000 psi
What is the ultimate stress of mild steel?
Allowable stress would normally refer to design using Allowable Strength Design, also known as working strength design. In this the allowable stress is usually a fraction of the yield strength and can be different for uniform tension and bending. Typically mild steel has a yield strength of about fy=250MPa with allowable stresses in Tension, 0.6fy=150MPa Bending, 0.66fy=165MPa
If the ultimate shear strength of a steel plate is 42.000lb inch squared what force P is necessary to punch a 0.70m diameter hole in a 0.625inch in thick plate?
2.27 kips
What are the uses of steel rod reinforcement?
Concrete's best strength rating is in compression, as in equal force from either side. Its weakest rating is in its shear strength, as in force in different areas like snapping a pencil in your hands. To increase concretes shear strength, re-inforcing steel bar is used because of its high shear strength characteristics.
What is Stress value of steel?
Ultimate shear stress of Mild steel is 210N/sq mm
What is the ultimate shear strength of stainless steel 316 n 304 n 302?
It depends on how it is worked, but a minimum strength in tension is 80,000psi. In shear, it is 0.577 times the tension strength, or shear strength minimum = 46,000 psi
What is the ultimate stress of mild steel?
Allowable stress would normally refer to design using Allowable Strength Design, also known as working strength design. In this the allowable stress is usually a fraction of the yield strength and can be different for uniform tension and bending. Typically mild steel has a yield strength of about fy=250MPa with allowable stresses in Tension, 0.6fy=150MPa Bending, 0.66fy=165MPa
If the ultimate shear strength of a steel plate is 42.000lb inch squared what force P is necessary to punch a 0.70m diameter hole in a 0.625inch in thick plate?
2.27 kips
What is the shear strength for 304 stainless steel?
For most steels . . . Shear Strength = 0.577 * UTS You can also say S.S = 0.577 * Yield and that would be the strength against yeilding.
What are the uses of steel rod reinforcement?
Concrete's best strength rating is in compression, as in equal force from either side. Its weakest rating is in its shear strength, as in force in different areas like snapping a pencil in your hands. To increase concretes shear strength, re-inforcing steel bar is used because of its high shear strength characteristics.
What is the meaning of steel re bar?
Rebar is an informal term for steel "reinforcing bar". These are steel bars that are placed within the structure before the wet concrete is placed. Steel reinforcement is necessary for almost all structural concrete because concrete has virtually no tensile or shear strength. The rebar provides almost all of the resistance to tension and shear within the structure.
When is reinforcement-bar required in footings?
Two reasons: shear and tension Concrete is strong in compression, but weak in tension, when you apply a vertical downward force upon the footing from the wall/ column it holds up, the top level is in compression (pushed toward the middle) but the bottom is in tension (pulled from the middle); the steel exists to make up for the low tensile strength of concrete in those regions. Concrete also has mid level shear strength, not entirely weak, but simultaneously requiring some help from steel stirrups, which act as compressive steel when the footing is in shear. Another major reason is the variability in concrete strength that can occur depending on mix, aggregate, pour etc, whereas steel is generally known in its properties, low variability, it can make up for the weakness of concrete that can occur.
What is Stress value of steel?
Ultimate shear stress of Mild steel is 210N/sq mm
WHAT IS COMPRESSION STRENGTH OF AISI 1045?
The AISI 1045 Medium Carbon Steel has a Shear Strength of 80 GPa.
What is the ultimate compressive strength of steel?
415
Can a 4 inch steel pipe handle a 50000 pound axial load?
Steel has a crush strength of 95,000 psi and a tensile strength of 55,000 psi. A Sch. 80 - 4" steel pipe has a cross-sectional area (of steel) of 4.407 sq. in. This can handle a load in tension of ~242,000 pounds before failure. And a load in compression of ~ 418,000 pounds before failure. 50,000 pounds is well within the factor of safety for both loads in tension or in compression, provided there are no shear forces applied.
How does the strength compare between a steel rod and a steel cable of the same weight?
the rod will be stronger, but will break, the cable will bend under force, but not break. the rod has more tensile and shear strength.
