Information On ultimate tensile strength

Ultimate tensile strength (UTS , often shortened to tensile strength (TS or ultimate strength is the maximum stress (mechanics) that a material can withstand before [[necking (engineering)|necking]] which is when the specimens cross-section starts to significantly contract. The UTS is usually found by performing a tensile test and recording the stress versus strain (engineering) the highest point of the stress-strain curve is the UTS. It is an Intensive and extensive properties therefore its value does not depend on the size of the test specimen. However, it is dependent on other factors, such as the preparation of the specimen and the temperature of the test environment and material. Tensile strengths are rarely used in the design of ductile members, however they are important in brittle members. They are tabulated for common materials such as alloy , composite material , ceramic , plastic and wood Tensile strength is defined as a stress, which is measured as force per unit area In the SI the unit is pascal (unit) (Pa) or, equivalently, Newton (unit) per square metre (N/m²). The customary unit is pounds-force per square inch (lbf/in² or psi), or kilo-pounds per square inch (ksi), which is equal to 1000 psi; kilo-pounds per square inch are commonly used for convienence when measuring tensile strengths.

Concept

Ductile materials

Image:Stress v strain Aluminum 2.png lt;br> 5. Offset strain (typically 0.2%)]] Image:Stress v strain A36 2.svg region
5. Necking region
A: Engineering stress
B: True stress]] Many materials display linear elastic behavior, defined by a linear stress-strain relationship, as shown in the figure up to point 2, in which deformation (engineering) are completely recoverable upon removal of the load - that is, a specimen loaded elastically in tension will elongate, but will return to its original shape and size when unloaded. Beyond this linear region, for ductile materials, such as steel, deformations are plastic deformation A plastically deformed specimen will not return to its original size and shape when unloaded. Note that there will be elastic recovery of a portionof the deformation. For many applications, plastic deformation is unacceptable, and is used as the design limitation. After the yield point, ductile metals will undergo a period of strain hardening, in which the stress increases again with increasing strain, and they begin to Necking (engineering) as the cross-sectional area of the specimen decreases due to plastic flow. In a sufficiently ductile material, when necking becomes substantial, it causes a reversal of the engineering stress-strain curve (curve A); this is because the engineering stressis calculated assuming the original cross-sectional area before necking. The reversal point is the maximum stress on the engineering stress-strain curve, and the engineering stress coordinate of this point is the tensile ultimate strength, given by point 1. The UTS is not used in the design of ductile static members because design practices dictate the use of the yield stress It is, however, used to for quality control, because of the ease of testing. It is also used to rough determine material types for unknown samples.http://www.ndt-ed.org/EducationResources/CommunityCollege/Materials/Mechanical/Tensile.htm

Brittle materials

Brittle materials, such as concrete and carbon fiber are characterized by failure at small strains. They often fail while still behaving in a linear elastic manner, and thus do not have a defined yield point. Because strains are low, there is negligible difference between the engineering stress and the true stress. Testing of several identical specimens will result in different failure stresses, this is due to the Weibull Modulus of the brittle material. The UTS is a common engineering parameter when design brittle members, because there is no yield point

Liquids

Tensile strength can be defined for liquid as well as solids. For example, when a tree draws water from its roots to its upper leaves by transpiration the column of water is pulled upwards from the top by capillary action and this force is transmitted down the column by its tensile strength.Citation needed|dateAugust 2010}}

Testing

File:Al tensile test.jpg lt;!-- Im working on making this into a real article --> Typically, the testing involves taking a small sample with a fixed cross-section area, and then pulling it with a controlled, gradually increasing force until the sample changes shape or breaks. When testing metals, indentation hardness correlates linearly with tensile strength. This important relation permits economically important nondestructive testing of bulk metal deliveries with lightweight, even portable equipment, such as hand-held Rockwell hardness testers.http://www.springerlink.com/content/q86642448t84g267/ Correlation of Yield Strength and Tensile Strength with Hardness for Steels , E.J. Pavlina and C.J. Van Tyne, Journal of Materials Engineering and Performance, Volume 17, Number 6 / December, 2008]

Typical tensile strengths

Some typical tensile strengths of some materials: | class "wikitable sortable" |- ! Material !! Yield strength
(MPa) !! Ultimate strength
(MPa) !! Density
(g/cm³) |- | first carbon nanotube ropes || ? || 3,600 || 1.3 |- | Structural steel ASTM A36 steel || 250 || 400 || 7.8 |- | carbon steel 1090 || || 841 || 7.58 |- | Steel, API 5L X65http://www.usstubular.com/products/seamslp.htm USStubular.com] || 448 || 531 || 7.8 |- | Steel, high strength alloy ASTM A514 steel || 690 || 760 || 7.8 |-yer maw | High tensile steel || 1,650 || 1,860|| 7.8 |- | Steel (AISI 1060 0.6% carbon) Piano wire || || 2,200-2,482http://www.djaerotech.com/dj_askjd/dj_questions/musicwire.html Don Stackhouse @ DJ Aerotech] || 7.8 |- | High density polyethylene (HDPE) || 26-33 || 37 || 0.95 |- | Polypropylene || 12-43 || 19.7-80 || 0.91 |- | Stainless steel AISI 302 - Cold-rolled || 520 || 860 || 8.19 |- | Cast iron 4.5% C, ASTM A-48 || 130 || 200 || |- | 4130 steel Citation needed|dateSeptember 2010}} || || 675 || 7.75 |- | Titanium alloy (6% Al, 4% V) || 830 || 900 || 4.51 |- | Beryllium http://www.matweb.com/search/datasheet.aspx?matguid9878e52807a249b8a6f3a6e4c179a732&ckck1 Beryllium I-220H Grade 2] 99.9% Be || 345 || 448 || 1.84 |- | Aluminium alloy http://www.matweb.com/search/DataSheet.aspx?MatGUIDe5de9f1161d34f71a34ae016723d097f Aluminum 2014-T6] 2014-T6 || 414 || 483 || 2.8 |- | Aluminium alloy 6063-T6 || || 248 || 2.63 |- | Copper 99.9% Cu || 70 || 220 || 8.92 |- | Cupronickel 10% Ni, 1.6% Fe, 1% Mn, balance Cu || 130 || 350 || 8.94 |- | Brass || 200+|| 550 || 5.3 |- | Tungsten || || 1,510 || 19.25 |- | Glass || || 33http://www.makeitfrom.com/data/?materialSoda_Lime_Glass Material Properties Data: Soda-Lime Glass] || 2.53 |- | Fibreglass || N/A || 3,450 || 2.57 |- | Fibreglass || N/A || 4,710 || 2.48 |- | Basalt fiber lt;ref>lt;/ref> || N/A || 4,840 || 2.7 |- | Marble || N/A || 15 || |- | Concrete || N/A || 3(traction) 30(compression) || |- | Carbon Fiber || N/A || 5,650 || 1.75 |- | Human hair || || 380 || |- | Bamboo || || 265 || 0.4 |- | Spider silk (See note below) || || 1,000 || 1.3 |- | Silkworm silk || 500 || || 1.3 |- | Aramid (Kevlar or Twaron || 3,620 || 2,757 || 1.44 |- | Ultra high molecular weight polyethylene | 23 || 46 || 0.97 |- | UHMWPE fibershttp://www-lgm2b.iut.u-bordeaux1.fr/publi/PE%20fibre.pdf Tensile and creep properties of ultra high molecular weight PE fibres]http://www.mse.mtu.edu/~drjohn/my4150/props.html Mechanical Properties Data] (Dyneema or Spectra) || || 2,300-3,500 || 0.97 |- | Vectran || || 2,850-3,340 || |- | Polybenzoxazole (Zylonhttp://www.toyobo.co.jp/e/seihin/kc/pbo/Technical_Information_2005.pdf Zylon Properties Document]) || || 5,800 || 1.56 |- | Toray carbon fiber T1000G (T1000Ghttp://www.toraycfa.com/pdfs/T1000GDataSheet.pdf Toray Properties Document]) || || 6,370|| 1.80 |- | Pine wood (parallel to grain) || || 40 || |- | Bone (limb) || 104-121 || 130 || 1.6 |- | Nylon type 6/6 || 45 || 75 || 1.15 |- | Rubber || - || 15 || |- | Boron || N/A || 3,100 || 2.46 |- | Silicon monocrystalline (m-Si) || N/A || 7,000 || 2.33 |- | Silicon carbide (SiC) || N/A || 3,440 || |- | Ultra-pure silca glass fiber-optic strandshttp://www.fols.org/fols_library/white_papers/documents/Fiber%20Myths%20White%20Paper%20final.pdf || || 4100 || |- | Sapphire (Al₂O₃) || N/A || 1,900 || 3.9-4.1 |- | Carbon nanotube (see note below) || N/A || 11,000-63,000 || 0.037-1.34 |- | Carbon nanotube composites || N/A || 1,200http://www.iop.org/EJ/abstract/-search56864390.1/0957-4484/18/45/455709 IOP.org] Z. Wang, P. Ciselli and T. Peijs, Nanotechnology 18, 455709, 2007.|| N/A |- |} *Note: Multiwalled carbon nanotubes have the highest tensile strength of any material yet measured, with labs producing them at a tensile strength of 63 GPalt;/ref>, still well below their theoretical limit of 300 GPa The first nanotube ropes (20 mm long) whose tensile strength was published (in 2000) had a strength of 3.6 GPa. http://link.aip.org/link/?APPLAB/77/3161/1 "Tensile strength of single-walled carbon nanotubes directly measured from their macroscopic ropes"] by F. Li, H. M. Cheng, S. Bai, G. Su, and M. S. Dresselhaus. DOI:10.1063/1.1324984 The density is different depending on the manufacturing method, and the lowest value is 0.037 or 0.55(solid)lt;/ref>. *Note: many of the values depend on manufacturing process and purity/composition. *Note: human hair strength varies by ethnicity and chemical treatments. *Note on spider silk strength: The strength of spider silk is highly variable. It depends on many factors including type of silk (every spider can produce several different types for different purposes), the particular species, the age of the silk, the temperature, the humidity, the rate at which stress is applied during testing, the length of time the stress is applied and the way the silk is collected (forced silking or natural spinning)lt;/ref>. The value shown in the table, 1000 MPa, is roughly representative of the results from a few studies involving several different species of spider however specific results varied greatly.lt;/ref> | class "wikitable sortable" |+Typical UTS values for annealed elementsA.M. Howatson, P.G. Lund and J.D. Todd, "Engineering Tables and Data", p. 41 |- ! Element !! Youngs modulus (GPa) !! Proof or yield stress (MPa) !! Ultimate strength (MPa) |- | Aluminium || 70 || 15-20 || 40-50 |- | Copper || 130 || 33 || 210 |- | Gold || 79 || || 100 |- | Iron || 211 || 80-100 || 350 |- | Lead || 16 || || 12 |- | Nickel || 170 || 14-35 || 140-195 |- | Silicon || 107 || 5,000-9,000 || |- | Silver || 83 || || 170 |- | Tantalum || 186 || 180 || 200 |- | Tin || 47 || 9-14 || 15-200 |- | Titanium || 120 || 100-225 || 240-370 |- | Tungsten || 411 || 550 || 550-620 |- | Zinc (wrought) || 105 || || 110-200 |- |}

Information On ultimate tensile strength

Concept

Ductile materials

Brittle materials

Liquids

Testing

Typical tensile strengths

See also

References

Further reading

Take Earn Money Tour