הבדלים בין גרסאות בדף "יחס חוזק/משקל"

מתוך Climbing_Encyclopedia
קפיצה אל: ניווט, חיפוש
(Examples)
(טבלת השוואה בין חומרים שונים)
 
(21 גרסאות ביניים של אותו משתמש אינן מוצגות)
שורה 8: שורה 8:
  
  
 
+
==טבלת השוואה בין חומרים שונים==
The '''specific strength''' is a material's [[Strength of materials|strength (force per unit area at failure)]] divided by its [[density]].  It is also known as the '''strength-to-weight ratio''' or '''strength/weight ratio''' or '''strength-to-mass ratio'''. In fiber or textile applications, [[Tenacity (textile strength)|tenacity]] is the usual measure of specific strength. The SI unit for specific strength is [[Pascal (unit)|Pa]] [[metre|m]]<sup>3</sup>/[[kilogram|kg]], or [[Newton (unit)|N]]·m/kg, which is [[Dimensional analysis|dimensionally equivalent]] to m<sup>2</sup>/s<sup>2</sup>, though the latter form is rarely used.
 
 
 
Another way to describe specific strength is '''breaking length''', also known as '''self support length''': the maximum length of a vertical column of the material (assuming a fixed cross-section) that could suspend its own weight when supported only at the top. For this measurement, the definition of [[weight]] is the force of [[gravity]] at the Earth's surface ([[standard gravity]], 9.80665&nbsp;m/s<sup>2</sup>) applying to the entire length of the material, not diminishing with height. This usage is more common with certain specialty fiber or textile applications.
 
 
 
The materials with the highest specific strengths are typically fibers such as [[carbon fiber]], [[glass fiber]] and various polymers, and these are frequently used to make [[composite material]]s (e.g.  [[Carbon fiber-reinforced polymer|carbon fiber-epoxy]]). These materials and others such as [[titanium]], [[aluminium]], [[magnesium]] and high strength steel alloys are widely used in [[aerospace]] and other applications where weight savings are worth the higher material cost.
 
 
 
Note that strength and stiffness are distinct. Both are important in design of efficient and safe structures.
 
 
 
==Examples==
 
  
 
{| class="wikitable sortable" style="text-align:right" style="margin: 1em auto 1em auto"
 
{| class="wikitable sortable" style="text-align:right" style="margin: 1em auto 1em auto"
 
|+ יחס חוזק/משקל של חומרים שונים
 
|+ יחס חוזק/משקל של חומרים שונים
! Material !! data-sort-type="number" | [[Tensile strength]] <br /> ([[Megapascal|MPa]])!! data-sort-type="number" |[[Density]] <br /> ([[Gram|g]]/[[Cubic centimetre|cm³]])!! data-sort-type="number" | Specific strength<br /> ([[Kilonewton|kN]]·[[Metre|m]]/[[Kilogram|kg]]) !! data-sort-type="number" |Breaking length <br />([[Kilometre|km]]) !! Source
+
! Material !! data-sort-type="number" | [[חוזק לקריעה]] <br /> (MPa)!! data-sort-type="number" |[[Density]] <br /> (g/cm³)!! data-sort-type="number" | יחס חוזק/משקל<br /> (kN·m/kg) !! data-sort-type="number" |אורך הנשיאה העצמי <br />(km) !! Source
 
|- align="right"
 
|- align="right"
 
| align="left"| בטון || 2–5 || 2.30 || 5.22 || 0.44 ||
 
| align="left"| בטון || 2–5 || 2.30 || 5.22 || 0.44 ||
שורה 29: שורה 20:
 
| align="left"| נחושת || 220 || 8.92 || 24.7 || 2.51 ||  
 
| align="left"| נחושת || 220 || 8.92 || 24.7 || 2.51 ||  
 
|- align="right"
 
|- align="right"
| align="left"| [[פוליפרופילן]] / PP || 25–40 || 0.90 || 28–44 || 2.8–4.5 || <ref>http://www.goodfellow.com/E/Polypropylene.html</ref>
+
| align="left"| [[פוליפרופילן]] / PP || 25–40 || 0.90 || 28–44 || 2.8–4.5 ||
|- align="right"
+
[http://www.goodfellow.com/E/Polypropylene.html]
| align="left"| (Poly)[[acrylonitrile-butadiene-styrene]] / ABS || 41–45 || 1.05 || 39–43 ||  || <ref>http://www.goodfellow.com/E/Polyacrylonitrile-butadiene-styrene.html</ref>
 
|- align="right"
 
| align="left"| פוליאסטר / Polyester / PET || 80 || 1.3–1.4 || 57–62 ||  || <ref>http://www.goodfellow.com/E/Polyethylene-terephthalate.html</ref>
 
 
|- align="right"
 
|- align="right"
| align="left"| [[Piano wire]] / ASTM 228 Steel || 1590-3340 || 7.8 || 204-428 ||  || <ref>http://www.matweb.com/search/datasheet_print.aspx?matguid=4bcaab41d4eb43b3824d9de31c2c6849</ref>
+
| align="left"| פוליאסטר / Polyester / PET || 80 || 1.3–1.4 || 57–62 ||  ||
 +
[http://www.goodfellow.com/E/Polyethylene-terephthalate.html]
 
|- align="right"
 
|- align="right"
| align="left"| [[Polylactic acid]] / Polylactide / PLA || 53 || 1.24 || 43 || || <ref>http://www.goodfellow.com/E/Polylactic-acid-Biopolymer.html</ref>
+
| align="left"| פלדה דלת פחמן (AISI 1010) || 365 || 7.87 || 46.4 || 4.73 ||  
 +
[http://www.matweb.com/search/datasheetText.aspx?bassnum=M1010A]
 
|- align="right"
 
|- align="right"
| align="left"| פלדה דלת פחמן (AISI 1010) || 365 || 7.87 || 46.4 || 4.73 || <ref>{{Cite web|title = AISI 1010 Steel, cold drawn |url = http://www.matweb.com/search/datasheetText.aspx?bassnum=M1010A | website = matweb.com|accessdate = 2015-10-20}}</ref>
+
| align="left"| פלב״מ (נירוסטה) (304) ||505 || 8.00 || 63.1 || 6.4 ||  
 +
[http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MQ304A]
 
|- align="right"
 
|- align="right"
| align="left"| פלב״מ (נירוסטה) (304) ||505 || 8.00 || 63.1 || 6.4 || <ref>{{Cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MQ304A|website = asm.matweb.com|accessdate = 2015-10-20}}</ref>
+
| align="left"| ברונזה || 580 || 8.55 || 67.8 || 6.91 || [http://www.roymech.co.uk/Useful_Tables/Matter/Copper_Alloys.html]
 
|- align="right"
 
|- align="right"
| align="left"| ברונזה || 580 || 8.55 || 67.8 || 6.91 || <ref name="roymech">{{cite web|url=http://www.roymech.co.uk/Useful_Tables/Matter/Copper_Alloys.html|title=Properties of Copper Alloys|work=roymech.co.uk}}</ref>
+
| align="left"| [[ניילון]] || 78 || 1.13 || 69.0 || 7.04 || [http://www.goodfellow.com/E/Polyamide-Nylon-6.html]
 
|- align="right"
 
|- align="right"
| align="left"| [[ניילון]] || 78 || 1.13 || 69.0 || 7.04 || <ref>http://www.goodfellow.com/E/Polyamide-Nylon-6.html</ref>
+
| align="left" | טיטניום || 344 || 4.51 || 76 || 7.75 ||  
 +
[http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MTU020]
 
|- align="right"
 
|- align="right"
| align="left" | טיטניום || 344 || 4.51 || 76 || 7.75 || <ref>{{cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MTU020|website = asm.matweb.com|accessdate = 2016-11-14}}</ref>
+
| align="left" | 41xx פלדת כרומולי (4130) || 560–670 || 7.85 || 71–85 || 7.27–8.70 ||  
 +
[http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=m4130r]
 
|- align="right"
 
|- align="right"
| align="left" | [[41xx פלדת |CrMo Steel]] (4130) || 560–670 || 7.85 || 71–85 || 7.27–8.70 || <ref>{{Cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=m4130r |website = asm.matweb.com|accessdate = 2016-08-18}}</ref><ref>{{Cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=M4130A |website = asm.matweb.com|accessdate = 2016-08-18}}</ref>
+
| align="left" | 6061 [[סגסוגות אלומיניום|סגסוגת אלומיניום]] (6061-T6) || 310 || 2.70 || 115 || 11.70 ||  
 +
[http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA6061T6]
 
|- align="right"
 
|- align="right"
| align="left" | [[6061 סגסוגת אלומיניום]] (6061-T6) || 310 || 2.70 || 115 || 11.70 || <ref>{{Cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA6061T6 |website = asm.matweb.com|accessdate = 2016-08-18}}</ref>
+
| align="left"| עץ אלון || 90 || 0.78–0.69 || 115–130 || 12–13 ||  
 +
[https://web.archive.org/web/20071009144917/http://www.io.tudelft.nl/research/dfs/idemat/Onl_db/Id192p.htm]
 
|- align="right"
 
|- align="right"
| align="left"| [[Oak]] || 90 || 0.78–0.69 || 115–130 || 12–13 || <ref>{{cite web |url=http://www.io.tudelft.nl/research/dfs/idemat/Onl_db/Id192p.htm |title=Environmental data: Oak wood |accessdate=2006-04-17 |deadurl=bot: unknown |archiveurl=https://web.archive.org/web/20071009144917/http://www.io.tudelft.nl/research/dfs/idemat/Onl_db/Id192p.htm |archivedate=9 October 2007 |df= }}</ref>
+
| align="left"| סגסוגת מגנזיום || 275 || 1.74 || 158 || 16.1 ||
 +
[http://www.efunda.com/Materials/alloys/magnesium/properties.cfm]
 
|- align="right"
 
|- align="right"
| align="left"| [[Inconel]] (X-750) || 1250 || 8.28 || 151 || 15.4 || <ref>{{Cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=NINC35|website = asm.matweb.com|accessdate = 2015-10-20}}</ref>
+
| align="left" | סגסוגת אלומיניום (7075-T6) || 572 || 2.81 || 204 || 20.8 ||  
 +
[http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA7075T6]
 
|- align="right"
 
|- align="right"
| align="left"| סגסוגת מגנזיום || 275 || 1.74 || 158 || 16.1 || <ref>{{cite web|url=http://www.efunda.com/Materials/alloys/magnesium/properties.cfm|title=eFunda: Typical Properties of Magnesium Alloys|publisher=}}</ref>
+
| align="left" | סגסוגת טיטניום (Beta C)|| 1250 || 4.81 || 260 || 26.5 ||
 +
[http://www.azom.com/article.aspx?ArticleID=1843]
 
|- align="right"
 
|- align="right"
| align="left" | [[סגסוגת אלומיניום]] (7075-T6) || 572 || 2.81 || 204 || 20.8 || <ref>{{Cite web|title = ASM Material Data Sheet|url = http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA7075T6|website = asm.matweb.com|accessdate = 2015-10-20}}</ref>
+
| align="left"| עץ בלזה || 73 || 0.14 || 521 || 53.2 ||
 +
[http://www.matweb.com/search/DataSheet.aspx]
 
|- align="right"
 
|- align="right"
| align="left" | סגסוגת טיטניום (Beta C) || 1250 || 4.81 || 260 || 26.5 || <ref>{{cite web|title = AZo Materials Data Sheet|url = http://www.azom.com/article.aspx?ArticleID=1843|website = azom.com|accessdate = 2016-11-14}}</ref>
+
| align="left"| סיבי פחמן + אפוקסי || 1240 || 1.58 || 785 || 80.0 ||  
|- align="right"
+
McGRAW-HILL ENCYCLOPEDIA OF Science & Technology, 8th Edition, (c)1997, vol. 1 p 375
| align="left"| [[Bainite]] || 2500 || 7.87 || 321 || 32.4 || <ref name="Bhadeshia">
 
[https://web.archive.org/web/20060828062831/http://www.msm.cam.ac.uk/phase-trans/2005/chunk.html 52nd Hatfield Memorial Lecture: "Large Chunks of Very Strong Steel"] by H. K. D. H. Bhadeshia 2005. [https://archive.is/20121223005514/http://www.msm.cam.ac.uk/phase-trans/2005/chunk.html on archive.is]
 
</ref>
 
|- align="right"
 
| align="left"| עץ בלזה || 73 || 0.14 || 521 || 53.2 || <ref>{{cite web|url=http://www.matweb.com/search/DataSheet.aspx?MatGUID=368427cdadb34b10a66b55c264d49c23|title=MatWeb - The Online Materials Information Resource|work=matweb.com}}</ref>
 
|- align="right"
 
| align="left"| סיבי פחמן + אפוקסי || 1240 || 1.58 || 785 || 80.0 || <ref>
 
McGRAW-HILL ENCYCLOPEDIA OF Science & Technology, 8th Edition, (c)1997, vol. 1 p 375</ref>
 
 
|- align="right"
 
|- align="right"
 
| align="left"| קורי עכביש || 1400 || 1.31 || 1069 || 109 ||
 
| align="left"| קורי עכביש || 1400 || 1.31 || 1069 || 109 ||
 
|- align="right"
 
|- align="right"
| align="left"| [[Silicon carbide]] fiber || 3440 || 3.16 || 1088 || 110 || <ref>[http://www.specmaterials.com/silicarbsite.htm Specialty Materials, Inc SCS Silicon Carbide Fibers]</ref>
+
| align="left"| סיבי סיליקון || 3440 || 3.16 || 1088 || 110 ||
|- align="right"
+
[http://www.specmaterials.com/silicarbsite.htm]
| align="left"| [[Glass fiber]] || 3400 || 2.60 || 1307 || 133 || <ref name="vectran">{{cite web |url = http://www.vectranfiber.com/properties/tensile-properties/|title = Vectran|publisher = Vectran Fiber, Inc.}}</ref>
 
|- align="right"
 
| align="left"| [[Basalt fiber]] || 4840 || 2.70 || 1790 || 183 || <ref>{{cite web|url=http://www.rwcarbon.com|title=RWcarbon.com - The Source for BMW & Mercedes Carbon Fiber Aero Parts|work=rwcarbon.com}}</ref>
 
|- align="right"
 
| align="left"| 1 μm [[iron]] [[Monocrystalline whisker|whiskers]] || 14000 || 7.87 || 1800 || 183 || <ref name="Bhadeshia" />
 
|- align="right"
 
| align="left"| [[Vectran]] || 2900 || 1.40 || 2071 || 211 || <ref name="vectran" />
 
|- align="right"
 
| align="left"| [[Carbon fiber]] (AS4) || 4300 || 1.75 || 2457 || 250 || <ref name="vectran" />
 
|- align="right"
 
| align="left"| [[Kevlar]] || 3620 || 1.44 || 2514 || 256 || <ref name="ngcc">{{cite web |url=http://www.ngcc.org.uk/info/ch1.html |title=Network Group for Composites in Construction: Introduction to Fibre Reinforced Polymer Composites |accessdate=2006-04-17 |deadurl=bot: unknown |archiveurl=https://web.archive.org/web/20060118112908/http://www.ngcc.org.uk/info/ch1.html |archivedate=January 18, 2006 |df= }}</ref>
 
|- align="right"
 
| align="left"| [[דיינימה]] ([[Ultra-high-molecular-weight polyethylene|UHMWPE]]) || 3600 || 0.97 || 3711 || 378 || <ref>{{cite web |title= Dyneema Fact sheet | publisher = [[DSM (Company)|DSM]] |url= http://www.dsm.com/products/dyneema/en_GB/home.html |date= {{date|2008-01-01}} }}</ref>
 
 
 
|- align="right"
 
| align="left"| [[Zylon]] || 5800 || 1.54 || 3766 || 384 || <ref name="Toyobo Co., Ltd.">{{Cite web|author=Toyobo Co., Ltd.|title=ザイロン®(PBO 繊維)技術資料 (2005)|url=http://www.toyobo.co.jp/seihin/kc/pbo/technical.pdf|format=free download PDF|deadurl=yes|archiveurl=https://web.archive.org/web/20120426001116/http://www.toyobo.co.jp/seihin/kc/pbo/technical.pdf|archivedate=2012-04-26|df=}}</ref>
 
|- align="right"
 
 
 
| align="left"| סיבי פחמן (Toray T1100G) ||7000 ||1.79 ||3911 || 399 ||<ref name="Toray Composites Materials America, Co., Ltd.">{{Cite web|author=Toray Composites Materials America, Co., Ltd.
 
|title=T1100S, INTERMEDIATE MODULUS CARBON FIBER|url=https://www.toraycma.com/file_viewer.php?id=5136|format=free download PDF}}</ref>
 
 
 
|- align="right"
 
| align="left"| [[Carbon nanotube]] (see note below) || 62000 || 0.037–1.34 || 46268–N/A || 4716–N/A || <ref name="Strength and Breaking">{{Cite journal |first1=Min-Feng |last1=Yu |date=28 January 2000 |title=Strength and Breaking Mechanism of Multiwalled Carbon Nanotubes Under Tensile Load |doi=10.1126/science.287.5453.637 |journal=Science |volume=287 |issue=5453 |pages=637–640 |pmid=10649994 |last2=Lourie |first2=Oleg |last3=Dyer |first3=Mark J. |last4=Moloni |first4=Katerina |last5=Kelly |first5=Thomas F. |last6=Ruoff |first6=Rodney S. |bibcode=2000Sci...287..637Y |url=http://www.bimat.org/assets/pdf/00_287yu.pdf}}</ref><ref name="K.Hata">{{Cite web|author=K.Hata|title=From Highly Efficient Impurity-Free CNT Synthesis to DWNT forests, CNTsolids and Super-Capacitors |url=http://www.nanocarbon.jp/english/research/image/review.pdf |doi=10.1117/12.716279}}</ref>
 
 
|- align="right"
 
|- align="right"
| align="left"| Miralon [[carbon nanotube]] yarn C-series || 1375 || 0.7–0.9 || 1100 || 112 || <ref name="NanoComp">{{Cite web|author=NanoComp Technologies Inc. |title=Miralon Yarn |url=https://cdn2.hubspot.net/hubfs/339583/Offers/Miralon_Yarn.pdf}}</ref>
+
| align="left"| סיבי זכוכית || 3400 || 2.60 || 1307 || 133 ||
 +
[http://www.vectranfiber.com/properties/tensile-properties/]
 
|- align="right"
 
|- align="right"
| align="left"| [[Colossal carbon tube]] || 6900 || .116 || 59483 || 6066 || <ref name="CCT">{{cite journal |author1=Peng, H. |author2=Chen, D. |author3=et al., Huang J.Y. | year = 2008 | title = Strong and Ductile Colossal Carbon Tubes with Walls of Rectangular Macropores | journal = Phys. Rev. Lett. | volume = 101 | issue = 14 | pages = 145501 | doi = 10.1103/PhysRevLett.101.145501 | pmid = 18851539 | bibcode=2008PhRvL.101n5501P|display-authors=etal}}</ref>
+
| align="left"| [[קבלר]] || 3620 || 1.44 || 2514 || 256 ||  
 +
[https://web.archive.org/web/20060118112908/http://www.ngcc.org.uk/info/ch1.html]
 
|- align="right"
 
|- align="right"
| align="left"| [[Graphene]] || 130500 || 2.090 <!--0.7e-6/0.335e-9 --> || 62453 || 6366 || <ref name="nobelprize.org">{{cite web |url=http://www.nobelprize.org/nobel_prizes/physics/laureates/2010/advanced-physicsprize2010.pdf |title=2010 Nobel Physics Laureates |publisher=nobelprize.org}}</ref>
+
| align="left"| [[דיינימה]] (Ultra-high-molecular-weight polyethylene: UHMWPE)
 +
|| 3600 || 0.97 || 3711 || 378 ||  
 +
[https://www.dsm.com/products/dyneema/en_GB/home.html]
 
|- align="right"
 
|- align="right"
| align="left"| Fundamental limit || || ||{{val|9|e=13}} ||{{val|9.2|e=12}} || <ref name="Brown 2012">{{cite journal |last=Brown |first=Adam R. |arxiv=1207.3342 |title=Tensile Strength and the Mining of Black Holes |date=2012 |version= |doi=10.1103/PhysRevLett.111.211301 |volume=111 |issue=21 |journal=Physical Review Letters |bibcode=2013PhRvL.111u1301B}}</ref>
+
| align="left"| סיבי פחמן (Toray T1100G) ||7000 ||1.79 ||3911 || 399 ||
 +
[www.toraycma.com/file_viewer.php?id=5136]
 
|- align="right"
 
|- align="right"
 
|}
 
|}
 
הנתונים בטבלה אינם נתונים הנדסיים, והם רק על מנת לתת אומדן גס של היכולות של חומרים שונים, כמובן.
 
הנתונים בטבלה אינם נתונים הנדסיים, והם רק על מנת לתת אומדן גס של היכולות של חומרים שונים, כמובן.
  
==The 'Yuri' and space tethers==
+
==קישורים חיצוניים==
The [[International Space Elevator Consortium]] has proposed the "Yuri" as a name for the SI units describing specific strength.  Specific strength is of fundamental importance in the description of [[space elevator]] cable materials. One Yuri is conceived to be the SI unit for yield stress (or breaking stress) per unit of density of a material under tension.  So, the units for one Yuri are ''Pa m<sup>3</sup> / kg''.  This unit is equivalent to one [[Newton (unit)|N]] [[meter|m]] / [[kilogram|kg]], which is the breaking/yielding ''force'' per ''linear'' density of the cable under tension.<ref>[https://web.archive.org/web/20160114223616/http://www.isec.org/images/StrongTetherChallenge/2013/Handbook-ts2013.rev0.pdf Strong Tether Challenge 2013]</ref><ref>{{cite web|url=http://www.isec.org/sec/index.php/about-the-space-elevator/terminology#MegaYuri|title=Terminology|author=Super User|work=isec.org|deadurl=yes|archiveurl=https://web.archive.org/web/20120527065913/http://www.isec.org/sec/index.php/about-the-space-elevator/terminology#MegaYuri|archivedate=2012-05-27|df=}}</ref>  A functional Earth [[space elevator]] would require a tether of 30-80 MegaYuri (corresponding to 3100–8200&nbsp;km of breaking length).<ref>{{cite web|url=http://keithcu.com/wiki/index.php/Specific_Strength_in_Yuris|title=Specific Strength in Yuris|work=keithcu.com}}</ref>
+
* [https://en.wikipedia.org/wiki/Specific_strength יחס חוזק/ משקל בויקיפדיה באנגלית]
 
+
* [http://www-materials.eng.cam.ac.uk/mpsite/interactive_charts/spec-spec/NS6Chart.html Specific stiffness - Specific strength] chart, University of Cambridge, Department of Engineering
==Fundamental limit on specific strength==
+
----
The null [[energy condition]] places a fundamental limit on the specific strength of any material.<ref name="Brown 2012"/> The specific strength is bounded to be no greater than c<sup>2</sup> ~ {{val|9|e=13}}[[Kilonewton|kN]]·[[Metre|m]]/[[Kilogram|kg]], where c is the [[speed of light]].  
+
תרמו לדף זה: [[משתמש: מיכה יניב|מיכה יניב]] ואחרים...
This limit is achieved by electric and magnetic field lines, [[QCD string|QCD flux tubes]], and the fundamental strings hypothesized by [[string theory]].{{cn|date=December 2018}}
 
 
 
==Tenacity (textile strength)==
 
{{About|the measure of fiber strength|the geologic term|Tenacity (mineralogy)|the herbicide|Mesotrione|other uses|Tenacious (disambiguation){{!}}Tenacious}}
 
  
'''Tenacity''' is the customary measure of [[Strength of materials|strength]] of a [[fiber]] or [[yarn]]. It is usually defined as the ultimate (breaking) force of the fiber (in [[gram]]-force units) divided by the [[Units of textile measurement#Denier|denier]].
+
[[קטגוריה: הגדרות]][[קטגוריה: טיפוס סלע]][[קטגוריה: טיפוס]][[קטגוריה: טיפוס ספורטיבי]][[קטגוריה: בטיחות]][[קטגוריה: מאמרים מתורגמים ומקוריים]]
Because denier is a measure of the linear density, the tenacity works out to be not a measure of force per unit area, but rather a quasi-dimensionless measure analogous to specific strength.<ref>{{cite book |title=Principles of Polymer Systems |first=Ferdinand |last=Rodriguez |page=282 |publisher=Hemisphere Publishing |location=New York |year=1989 |edition=3rd |isbn=9780891161769 |oclc=19122722}}</ref>
+
[[קטגוריה: טיפוס הרים]]
A tenacity of <math>1</math> corresponds to:{{cn|date=December 2018}} <math>\frac{1 {\rm \, g} \cdot 9.80665 {\rm \, m s^{-2}}}{1 {\rm \, g}/9000 {\rm \, m}}=\frac{9.80665 {\rm \, m s^{-2}}}{1/9000 {\rm \, m}}=9.80665  {\rm \, m s^{-2}} \, 9000 {\rm \, m} = 88259.85  {\rm \, m^2 s^{-2}} </math>
 
 
 
==See also==
 
* [[Specific modulus]]
 
* [[Space elevator]]
 
* [[Space tether]]
 
 
 
==References==
 
{{Reflist|2}}
 
 
 
==External links==
 
* [http://www-materials.eng.cam.ac.uk/mpsite/interactive_charts/spec-spec/NS6Chart.html Specific stiffness - Specific strength] chart, University of Cambridge, Department of Engineering
 

גרסה אחרונה מ־04:57, 17 באפריל 2019

יחס חוזק/משקלאו יחס חוזק למשקל, נקרא גם חוזק סגולי (באנגלית: specific strength, strength-to-weight ratio או strength/weight ratio או אפילו strength-to-mass ratio) הוא היחס בין החוזק של חומר (שמוגדר ככוח ליחידת שטח, או המאמץ ברגע הכשל) ובין הצפיפות שלו. בחומרים רכים כמו טקסטיל מדובר על כשל במשיכה. בחומרים קשים מדובר על כשל במשיכה או בדחיסה.

עוד דרך לתאר את החוזק הסגולי של חומר היא לבחון את האורך לכשל, או את אורך הנשיאה העצמי של החומר. נדמיין עמוד או מוט ארוך של החומר, שתלוי רק מלמעלה. ברור, שבאורך מספיק גדול, המקטע העליון לא יוכל לשאת את המשקל וייקרע. לצורך זה, הכוח שגורם לכשל הוא כוח הכבידה של כדור הארץ, שמחושב על פני כל האורך של עמודת החומר לקבלת המשקל בכשל. לדוגמה, חבל טיפוס ששוקל כ-60גרם למטר, יכול לשאת משקל של 2200קילוגרם, בערך. זה אומר שאורך הקריעה הנשיאה העצמי שלו הוא קצת יותר מ-36.5 ק״מ!

ברור, שחבל שלא יכול לשאת את משקלו העצמי לא יתפקד בכלל כחבל...



טבלת השוואה בין חומרים שונים

יחס חוזק/משקל של חומרים שונים
Material חוזק לקריעה
(MPa)
Density
(g/cm³)
יחס חוזק/משקל
(kN·m/kg)
אורך הנשיאה העצמי
(km)
Source
בטון 2–5 2.30 5.22 0.44
גומי 15 0.92 16.3 1.66
נחושת 220 8.92 24.7 2.51
פוליפרופילן / PP 25–40 0.90 28–44 2.8–4.5

[1]

פוליאסטר / Polyester / PET 80 1.3–1.4 57–62

[2]

פלדה דלת פחמן (AISI 1010) 365 7.87 46.4 4.73

[3]

פלב״מ (נירוסטה) (304) 505 8.00 63.1 6.4

[4]

ברונזה 580 8.55 67.8 6.91 [5]
ניילון 78 1.13 69.0 7.04 [6]
טיטניום 344 4.51 76 7.75

[7]

41xx פלדת כרומולי (4130) 560–670 7.85 71–85 7.27–8.70

[8]

6061 סגסוגת אלומיניום (6061-T6) 310 2.70 115 11.70

[9]

עץ אלון 90 0.78–0.69 115–130 12–13

[10]

סגסוגת מגנזיום 275 1.74 158 16.1

[11]

סגסוגת אלומיניום (7075-T6) 572 2.81 204 20.8

[12]

סגסוגת טיטניום (Beta C) 1250 4.81 260 26.5

[13]

עץ בלזה 73 0.14 521 53.2

[14]

סיבי פחמן + אפוקסי 1240 1.58 785 80.0

McGRAW-HILL ENCYCLOPEDIA OF Science & Technology, 8th Edition, (c)1997, vol. 1 p 375

קורי עכביש 1400 1.31 1069 109
סיבי סיליקון 3440 3.16 1088 110

[15]

סיבי זכוכית 3400 2.60 1307 133

[16]

קבלר 3620 1.44 2514 256

[17]

דיינימה (Ultra-high-molecular-weight polyethylene: UHMWPE) 3600 0.97 3711 378

[18]

סיבי פחמן (Toray T1100G) 7000 1.79 3911 399

[www.toraycma.com/file_viewer.php?id=5136]

הנתונים בטבלה אינם נתונים הנדסיים, והם רק על מנת לתת אומדן גס של היכולות של חומרים שונים, כמובן.

קישורים חיצוניים


תרמו לדף זה: מיכה יניב ואחרים...