तनाव पुष्टि

thumb|right|300px|निर्माण में प्रयुक्त इस्पात का प्रतिबल-विकृति ग्राफ 1. अधिकतम् सामर्थ्य (Ultimate Strength) 2. पराभव सामर्थ्य (Yield strength) 3. विभंजन (Rupture) 4. विकृति कठोरता क्षेत्र (Strain hardening region) 5. ग्रीवण क्षेत्र (Necking region) A: आभासी (इंजीनियरी) सामर्थ्य (Apparent (engineering) stress) (F/A0) B: वास्तविक (सत्य) प्रतिबल (F/A) किसी पदार्थ की तनन सामर्थ्य या तनाव पुष्टि (Tensile strength) (σUTS या SU) उस पदार्थ के प्रतिबल-विकृति वक्र (stress-strain curve) के महत्तम बिन्दु होता है तथा यह संकेत देता है कि किस प्रतिबल के बाद गर्दन बनना (necking) आरम्भ होगा। इसका मान परीक्षण के लिये ली गयी पदार्थ के नमूने के आकार (साइज) पर निर्भर नहीं करता। संरचनाओं (structures) तथा यांत्रिक युक्तियों में प्रयुक्त इंजीनियरी पदार्थों के लिये प्रत्यास्थता गुणांक तथा क्षरण प्रतिरोध (corrosion resistance) के साथ-साथ तनाव-पुष्टि अत्यन्त महत्व की राशि है। मिश्रधातुओं, कम्पोजिट पदार्थों, सिरैमिक्स, प्लास्टिकों, काष्ठ, कांक्रीट आदि के लिये इसके मान दिये जाते हैं। व्याख्या तनाव पुष्टि की तीन परिभाषाएँ हैं- (१) पराभव सामर्थ्य (Yield strength) जिस प्रतिबल पर पदार्थ की विकृति प्रत्यास्थ से अप्रत्यास्थ मे बदलने लगती है जिससे पदार्थ में स्थायी विकृति उत्पन्न हो जाती है। (२) अधिकतम सामर्थ्य (Ultimate strength) यह वह प्रतिबल है जो प्रतिबल-विकृति ग्राफ में अधिकतम् प्रतिबल की सूचक होती है। (३) विभंजक सामर्थ्य (Breaking strength) यह वह प्रतिबल-विकृति वक्र के उस बिन्दु पर प्रतिबल का मान है जिस पर वस्तु टूट (rupture) जाती है। कुछ पदार्थों के तनाव-पुष्टि कुछ पदार्थों के सामान्य तनाव पुष्टि के मान नीचे की सारणी में दिया गया है- पदार्थ Yield strength (MPa) Ultimate strength (MPa) घनत्व (g/cm³) कार्बन नैनोट्यूब की प्रथम रस्सियाँ ? 3,600 1.3 स्ट्रक्चरल स्टील ASTM A36 steel 250 400 7.8 Steel, API 5L X65http://www.usstubular.com/products/seamslp.htm USStubular.com 22 जनवरी 2010 https://web.archive.org/web/20100408105423/http://www.usstubular.com/products/seamslp.htm 8 अप्रैल 2010 dead 448 531 7.8 Steel, high strength alloy ASTM A514 690 760 7.8 Steel, prestressing strands 1,650 1,860June 2008 7.8 Steel Wire     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 22 जनवरी 2010 https://web.archive.org/web/20150923215324/http://www.djaerotech.com/dj_askjd/dj_questions/musicwire.html 23 सितंबर 2015 dead 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   Titanium alloy (6% Al, 4% V) 830 900 4.51 Berylliumhttp://www.matweb.com/search/datasheet.aspx?matguid=9878e52807a249b8a6f3a6e4c179a732&ckck=1 Beryllium I-220H Grade 2 22 जनवरी 2010 https://web.archive.org/web/20150221000023/http://www.matweb.com/search/datasheet.aspx?matguid=9878e52807a249b8a6f3a6e4c179a732&ckck=1 21 फ़रवरी 2015 dead 99.9% Be 345 448 1.84 Aluminium alloyhttp://www.matweb.com/search/DataSheet.aspx?MatGUID=e5de9f1161d34f71a34ae016723d097f Aluminum 2014-T6 22 जनवरी 2010 https://web.archive.org/web/20150221004359/http://www.matweb.com/search/DataSheet.aspx?MatGUID=e5de9f1161d34f71a34ae016723d097f 21 फ़रवरी 2015 dead 2014-T6 414 483 2.8 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   50 (in compression) 2.53 E-Glass N/A 3,450 2.57 S-Glass N/A 4,710 2.48 Basalt fiber Basalt Continuous Fibers http://www.albarrie.com/techfabrics/continuousfiber.aspx 2009-12-29 https://www.webcitation.org/5mO840Mwq?url=http://www.albarrie.com/techfabrics/continuousfiber.aspx 29 दिसंबर 2009 . dead N/A 4,840 2.7 Marble N/A 15   Concrete N/A 3   Carbon Fiber N/A 5,650 1.75 Human hair   380   Spider silk (See note below) 1,000   Silkworm silk 500     Aramid (Kevlar or Twaron) 3,620   1.44 UHMWPE 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 22 जनवरी 2010 https://web.archive.org/web/20070628154929/http://www-lgm2b.iut.u-bordeaux1.fr/publi/PE%20fibre.pdf 28 जून 2007 dead http://www.mse.mtu.edu/~drjohn/my4150/props.html Mechanical Properties Data 22 जनवरी 2010 https://web.archive.org/web/20070503113533/http://www.mse.mtu.edu/~drjohn/my4150/props.html 3 मई 2007 dead (Dyneema or Spectra) 2,300-3,500 0.97 Vectran   2,850-3,340   Polybenzoxazole (Zylon)   5,800   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   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 1,200IOP.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 GPa Min-Feng Yu 2000 Strength and Breaking Mechanism of Multiwalled Carbon Nanotubes Under Tensile Load https://archive.org/details/sim_science_2000-01-28_287_5453/page/636 10.1126/science.287.5453.637 Science 287 637–640 10649994 Lourie O Dyer MJ Moloni K Kelly TF Ruoff RS 5453, 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, still well below their theoretical limit."Tensile strength of single-walled carbon nanotubes directly measured from their macroscopic ropes" http://arquivo.pt/wayback/20160514133916/http://link.aip.org/link/?APPLAB/77/3161/1 14 मई 2016 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)K.Hata From Highly Efficient Impurity-Free CNT Synthesis to DWNT forests, CNTsolids and Super-Capacitors http://www.nanocarbon.jp/english/research/image/review.pdf free download PDF 22 जनवरी 2010 https://web.archive.org/web/20181215122421/http://nanocarbon.jp/english/research/image/review.pdf 15 दिसंबर 2018 dead. 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) Elices, et al. Finding Inspiration in Argiope Trifasciata Spider Silk Fibers JOM http://www.tms.org/pubs/journals/JOM/0502/Elices-0502.html 2009-01-23 https://web.archive.org/web/20090115152853/http://www.tms.org/pubs/journals/JOM/0502/Elices-0502.html 15 जनवरी 2009 dead . 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. Blackledge, et al. Quasistatic and continuous dynamic characterization of the mechanical properties of silk from the cobweb of the black widow spider Latrodectus hesperus The Company of Biologists http://jeb.biologists.org/cgi/content/full/208/10/1937 2009-01-23 https://web.archive.org/web/20090201084456/http://jeb.biologists.org/cgi/content/full/208/10/1937 1 फ़रवरी 2009 live Elements in the annealed state Young's 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 (स्रोत: A.M. Howatson, P.G. Lund and J.D. Todd, "Engineering Tables and Data" p41) सन्दर्भ इन्हें भी देखें संपीडन पुष्टि संरचना इंजीनियरी बाहरी कड़ियाँ Stress-strain diagram January 2003 sci.physics thread on water tensile strength and trees Theory re the discrepancy in static vs dynamic measurements of water's tensile strength Engineering Stress-strain Curve Systems for measuring tensile strength Testing equipment to determine properties of materials including Tensile strength श्रेणी:पदार्थ विज्ञान