Talk:Toughness

Talk
"...when suddenly stressed." : is the suddenly important/essential? Looks quite hard to pin down, and not very relevant surely? Out of my field, so I'll leave this one to someone more knowledgeable. 194.106.59.2 15:34, 25 Mar 2005 (UTC)

It says square inches1111, but then the math is inches cubed.


 * For some reason this confuses a lot of people. The correct units are energy/volume (J/m^3 or in-lbf/in^3).  This is dimensionally equivalent to force/area (N/m^2 or lbf/in^2).  Toiyabe 15:18, 9 April 2007 (UTC)

Toughness
It seems to me that the area under the stress/ strain curve is an indication of toughness but not the measure of toughness. Conventionally, the Izod or Charpy impact tests are used although the previous comment about the inexactness of defining "sudden" is valid. The Charpy and Izod tests give a value in Joules per square meter which then relates directly with the gamma term used by Griffith and the "G" used by Irwin in Fracture Mechanics equations. In this way, so-called Impact Toughness can be related to Fracture Toughness and the dimensional analysis balances.

Roger Tyler MSc

The area under the stress strain curve is twice the fracture energy per unit volume of a tensile sample; i.e. 'G'. This only hold when the stress-strain curve occurred through stable crack growth. Under stable crack growth the crack grows at equilibrium. Under unstable crack growth there is elastic energy which is transformed to kinetic energy of the two fractured half's. Toughness is not measured as Joules per square meter but as a pascal times squareroot(meter).


 * "Toughness is not measured as Joules per square meter but as a pascal times squareroot(meter)" You are confusing toghness and fracture toughness. T om ea s y T C 12:48, 14 July 2011 (UTC)

As with all mechanical properties tests, the toughness of a given material is only closely comparable to another material of similar anisotropy and general shape of stress-strain curve. It is however convenient and acceptable to make general statements comparing dissimilar materials, i.e. "metals are generally tougher than ceramics". — Preceding unsigned comment added by 131.215.115.31 (talk) 21:21, 4 April 2017 (UTC)

Toughness is measured in your bakkie - and the Hilux is the toughest bakkie around! — Preceding unsigned comment added by 41.161.36.26 (talk) 12:48, 15 September 2011 (UTC)

'''The simple understanding of tough..... a Toyota hilux is so tough it can even start a Land Rover.......and tear a hole in time!''

Malleability?
I was given to understand that toughness also indicated a combination of hardness and malleability. Is this relevant to the article? Is it correct? Mydogtrouble (talk) 20:36, 22 April 2010 (UTC)


 * Toughness is roughly inversely proportional to hardness and ductility, but it is not directly related. Wizard191 (talk) 20:58, 22 April 2010 (UTC)


 * No, it is roughly proportional to ductility. T om ea s y T C 12:41, 14 July 2011 (UTC)

Toughness is measured in J/m^2
It is the energy dissipated by creating a fracture surface of a certain size - the former is measured in Joule the latter in square meter, hence J/m^2.

Unfortunately the whole article talk about the senseless J/m^3, which would mean that the toughness of a rod under uniaxial tension is inversely proportional to its length, which is rubbish. For such a geometry, the toughness is a material property independent of the length of the rod.

I put this message here, because I plan to drastically change the article (provided I have the time to). If you disagree, please let me know. T om ea s y T C 12:46, 14 July 2011 (UTC)


 * ...except when it isn't. I've been doing research on the physical materials of plastics for a project and have noted that impact strength is measured in J/m or ft-lbs./in in a significant portion of the material data sheets I have been referencing. Some examples of it's use include the chart on page 40 of this design guide for Amodel brand plastic or this product information document for sheets of IPX plastic.
 * To get into other semantics, the article doesn't even use J∕m³, it uses J∙m⁻³, which is mathematically correct but is easy to misread as m³, (as you have done) because that makes much more sense in the manner in which people usually think about the value of units of length raised to a power (1 in² is equal in area to a square measuring 1 in in each direction, one light-year³ is equal to a cube measuring one light year in each direction, but what does m⁻³ mean? what does it mean to be in -3 dimensions?). Turrit hugger (talk) 14:00, 16 February 2022 (UTC)

Beyond Toughness
Beyond toughness describes what Toyota Hilux demonstrates and portrays. The unbeatable and unbreakable "workhorse" is an all round combination of durability, reliability and all round toughness...hence the "Beyond Toughness" terminology!]] — Preceding unsigned comment added by Zarabradshaw (talk • contribs) 13:59, 19 September 2011 (UTC)

Definition of toughness
"Material toughness is defined as the amount of energy per volume that a material can absorb before rupturing."

This unsubstantiated assertion is simply not true. Note the use of the passive voice in making the assertion, to which the proper response is to ask: Defined by whom, where and when? There is no SI definition of 'toughness'. There is no SI quantity called 'toughness'. There is no SI unit of 'toughness'. Toughness is a loose term akin to the term hardness in that there is no accepted definition by physicists. 'Toughness' and 'tough' are terms that are widely bandied around by materials technologists and engineers but not by physicists who know that there is no simple way of defining 'toughness'. Technologists and engineers are not scientists of course. They just want to get the job done, somehow, on time and on budget so that they can move on to the next project. A scientist who wants to understand the nature of toughness at the most fundamental level has a different perspective, and will admit that there are many different ways of trying to define, measure, and estimate toughness for materials and for structures. The opening sentence needs to be amended therefore to read as follows:

"One definition of material toughness is the amount of energy per volume that a material can absorb before rupturing."

I'm changing the sentence accordingly. Any editor who thinks they know better and wants to revert the edit needs to provide a reliable source to support their claim. 124.186.130.7 (talk) 04:38, 15 March 2013 (UTC)


 * Wow, someone is mad that their science degree doesn't earn them as much as engineers huh? All your points were covered in engineering school by the way, you elitist prick. Good edit though. 146.115.129.15 (talk) 17:25, 1 May 2013 (UTC)

Contradiction
The intro paragraph says something like "toughness requires a balance of strength and ductility". The 'Strength and Toughness' section says something like "Strength and toughness are unrelated". This is a clear contradiction and diminishes the credibility of the article. 146.115.129.15 (talk) 17:25, 1 May 2013 (UTC)

tear resistance?
Tear resistance? I'm looking at certain otherwise tough polymers with poor tear resistance. Seems like a toughness issue. No mention, link, or suggestion here? --71.137.156.36 (talk) 16:46, 18 April 2014 (UTC)Doug Bashford

Merge Toughness with Resilience (materials science)
Same definition, same units, same reference. Kbrose (talk) 19:56, 11 July 2015 (UTC) No. Resilience is a material's ability to absorb elastic energy. Toughness is energy required to fracture a given volume of material (i.e. elastic and PLASTIC deformation).

Specific toughness
Please add some words regarding resilience per mass. It's great that material 'A' is more resilient than material 'B', but for aerospace use, we want to be sure that 'A's increased performance over 'B' takes into account it's possibly higher density than 'B'. 2600:1700:4CA1:3C80:EDB4:6D26:C2A:536C (talk) 02:36, 11 November 2018 (UTC)

"Orders of magnitude (toughness)" listed at Redirects for discussion
An editor has asked for a discussion to address the redirect Orders of magnitude (toughness). Please participate in the redirect discussion if you wish to do so. Utopes (talk / cont) 06:28, 12 April 2020 (UTC)

"Joule per cube metre" listed at Redirects for discussion
An editor has asked for a discussion to address the redirect Joule per cube metre. Please participate in the redirect discussion if you wish to do so. Utopes (talk / cont) 06:29, 12 April 2020 (UTC)

Contradictory definitions
The first sentence says that toughness is ability to deform without fracturing. But then it claims toughness is measured by the area under the stress-strain curve. The latter has more to do with how difficult it is to deform the material away from its original shape ( https://en.m.wikipedia.org/wiki/Deformation_(physics)#Strain ). E.g., if the stress-strain curve rises sharply in the left - for greater total area - then that means a lot of stress would need to be applied before much strain (deformation) would result. But that's not a statement about when fracture occurs.

Perhaps both of these are used as definitions of "toughness" in different contexts, but if so, they should perhaps be separated into two different articles with a disambiguation page., or at least it should be made more clear that these are two different and incompatible definitions. Tim314 (talk) 17:13, 24 January 2023 (UTC)