Talk:Strength of materials

Materials science
Materials science differs from this in what way? —Preceding unsigned comment added by Sparky (talk • contribs) 07:50, January 22, 2004 Pud 20:52, 7 Sep 2004 (UTC)
 * (you can sign your dated name by adding four tildas. Oh, by the way, Hi Sparky)
 * 1) Materials science is far broader.
 * 2) Academically, they are taught as different subjects.
 * 3) In the real world, engineers use these disciplines separately; Materials science involves the development or choice of materials for engineering uses, and Strength of materials is applied to the design of mechanical elements. They are sometimes used in parallel and sometimes overlap. For example, a design engineer choosing a material for a specific application. But they are not the same subject. Professionally, material science is a different occupation than Design engineering or Analysis.
 * 1) Tensile Strength is a very important test for many materials (suture materials for example)  Merging this article into strength of materials would be a diservice to the community.  Are we going to start a trend of merging all subtopics into their parent topics?  Who wants to read a 60 page article on all the types and measurments of a material's strength?  CoolMike 13:08, 31 May 2006 (UTC)
 * 2) Tensile stress is the most important test to check the ability of the material —Preceding unsigned comment added by 122.181.135.140 (talk) 13:21, 27 January 2011 (UTC)

elasticity/plasticity edit
I decided to replace the existing text with a plain-English explanation of the concepts of elasticity and plasticity. I also deleted the paragraph about viscosity. Although I can see why creep is relevant, I did not feel like taking the effort to massage it into the section. Viscosity relates to fluids, and the article relates to solids, so I think it is out of place.

I will sign this properly when the servers come back up. Cbdorsett

Proposed merger
Please see the Talk:Tensile strength page for discussion (if any) Slinky Puppet 18:01, 11 January 2006 (UTC)
 * No support, I am calling off the merger and removing the links. Georgewilliamherbert 01:29, 22 September 2006 (UTC)

Fixes and additions
I fixed a bunch of stuff that was clearly wrong, and took out some stuff which didn't make sense.

I removed the part about Hooke's Law, as it doesn't belong in a strength of materials article, and will only confuse readers about the stress-strain relationship.

I also removed the comment about compressive stress that stated a material under compression will decrease in volume. This is simply wrong and needed to be removed. Sorry if I stepped on any toes, but I looked this up at work and my head almost exploded when I read it.

--Ryan 17:30, 21 June 2006 (UTC)


 * Most materials will in fact decrease in volume under compression. Look up the article on Poisson's ratio on wikipedia or google "volume strain". In my opinion, Hooke's law should be mentioned, as well as basic structural analysis methods. This article should reflect the topics covered in common ""Strength of materials"" engineering courses and books, which focus on stress-strain relations, beam and truss analysis, continuum mechanics, and material strength terms. Sigmund 11:58, 20 June 2007 (UTC)


 * About Hooke's law i think it should be added as it is mentioned in almost every book written on strength of materials and has a clear distinction to be added here. Kalivd (talk) 15:19, 24 September 2008 (UTC)


 * I also think that at least a brief mention of Hooke's Law is essential, as it provides the foundation for the theory of elasticity. (Any readers "confused" by it are likely barking up the wrong proverbial tree!). Fortunately, it is amply described and referenced in a number of other closely related articles on elasticity theory, such as solid mechanics, theory of elasticity and deformation (engineering). -- logger9 (talk) 17:13, 14 April 2009 (UTC)

Structural strength
A search for "structural strength" gives no useful results. My context is the use of that term on the hardboard article. Perhaps the term should be explained in this article?

Skarkkai 11:55, 17 June 2007 (UTC)

Case studies
The article is far too theoretical, so I have added an external link to real case studies of failure. The article itself also needs some cases as well. Any offers? Peterlewis 14:43, 20 June 2007 (UTC) we can use for the — Preceding unsigned comment added by 202.86.17.197 (talk) 09:45, 3 December 2011 (UTC)

page history
Some content (for example, some of the bibliographic references) has been merged from mechanics of materials, a list of whose authors might be found here. 69.140.152.55 (talk) 05:46, 27 September 2008 (UTC)

Split article?
In the wikipedia an article is always supposed to be on a single definition, that's what makes it WP:Wikipedia is not a dictionary. There seems to be two separate uses of the term 'strength of materials'. One is the materials science term which analyses the response of an engineering material, the other seems to be about how structures behave. These are logically distinct, and should be separated.

Maybe something like:

Strength of materials (material science)

Strength of materials (structures)

Comments?- (User) Wolfkeeper (Talk) 19:53, 22 November 2008 (UTC)


 * They are both fairly related. I don't think separate articles are needed for this.  Also, there are other related structures articles already like Solid mechanics, Structural analysis, Stress analysis, Elasticity (physics), etc. -Fnlayson (talk) 20:25, 22 November 2008 (UTC)
 * Strength of materials is a single topic. It happens that its concepts are used in structural analysis and for material testing. A single article is better. Sanpaz (talk) 21:33, 22 November 2008 (UTC)


 * I agree that they're related, but they're not the same thing. Articles are about a topic.- (User) Wolfkeeper (Talk) 22:10, 22/11/ 2008 (UTC)

strength of materials. Basic assumptions
Subject to strength of materials. Basic assumptions I. Introduction. All modern buildings, machinery, appliances and equipment are manufactured or built on pre-designed projects. The project is drawing or series of drawings and technical drawings, which sets out all dimensions of the elements of structures and details of the machinery necessary for their preparation, their materials and also describes the technology. Thus, even in the design process must be perfectly defined dimensions of the elements and details of equipment and machinery. Obviously these rates depend on a number of conditions and circumstances, including by properties of the material and the alleged external influences. Each structure must have the reliability in operation and be economical. Reliability of the structure shall be provided if it store strength, stiffness and stability with guaranteed durability. Its economy is largely determined by the cost of material from the application of less scarce construction materials the possibility of drawing up details of the most advanced technologies. Reliability and economy are contradictory requirements. Strength - this is the ability of the structure to resist destruction in its effect on the external forces (loads). Stiffness - this element is the ability to resist deformations. Sustainability - a property of the system to retain their primary balance in the external impacts. Durability of the structure consists of its ability to store the necessary properties for use in the course of earlier certain period of time. In strength of materials is widely applied methods theoretical mechanics and mathematical analysis, using data from sections of physics, studying the properties of different materials, and other Science. Strength of materials is a theoretical-experimental science, because it widely used experimental data and theoretical studies. First notes about the strength found in the notebooks of Leonardo da Vinci. Genesis of the science of strength of materials refers to the XVII century and is connected with the work of the famous scholar of that time Galileo Galilei. Significant contribution to this development was made by eminent scientists Hook, Bernoulli, Saint-Vena, Koshi, lame, Euler and others. In Russia at the end of the XIX and beginning of XX century, important research on resistance Materials scientists have made Russian Zhuravskiy I. D., U. S. Yasinskiy, I. D. Boubnova, S. P. Timoshenko and others. II. The main task of the strength of materials. The main task of the strength of materials is to development of engineering methods for designing and calculating typical elements of structures for strength, stiffness and stability durability, given simultaneously backing the economy. III. Real objects and computational scheme. In strength of materials study the question of reliability real object begins with the choice of computational scheme. The real object released from non-essential features, a computational scheme. The choice of computational scheme begins with the adoption of the basic assumptions. IV. Main hypotheses. Strength of Materials course aims at creating a practically acceptable simple ways to calculate the typical elements of structures. Need a practical decision of each task bring to the numerical result is the reason for engaging in many cases to simplifying assumptions. These are assumptions that are justified after compare the numerical results with those of experiments. 1. Hypotheses about the material. a) the assumption of continuity of the material. This is an environment occupying a constant volume. b) the assumption of homogeneity of the material. Under the uniformity means uniformity of properties in all points of the body. It is experimentally proved that the material has heterogeneous, discrete structure. However, when the volume of element volume surpasses many of the structural units composing it ( atoms, molecules), real bodies can be regarded as homogeneous. c) izotropnost hypothesis. Continuous medium is considered isotropic, ie have the same properties in all directions. This is steel. Are anisotropic materials whose properties in different directions are different (eg, wood). d) deformiruemost hypothesis. If the bodies in the theoretical mechanics is regarded as absolutely stiff, then in the resistance of the material bodies have the ability be deformed, ie to modify their initial size and shape under action of external loads. Deformations of the material in each section shall be adopted in relation to their small sizes and can not account their influence on the mutual disposition of the cargo (ie calculations are carried out in undistorted scheme). e) the hypothesis of elasticity. Elasticity is the property of their bodies to recover original shape and size after removal of the load. 2. Hypotheses about body shape. a) the main task of the strength of materials to be decided units of beam type. This is a body whose length is significantly greater than transverse dimensions. b) the hypothesis of plane sections (the Bernoulli hypothesis). Any sectional plane perpendicular to the axis of the beam before deformation remains plane and perpendicular to the axis of the deformed the beam at this location. F F 3. Hypotheses about the forces applied. a) distributed over a small area loads are considered concentrated. F b) the principle of Saint-Vena. If you replace a system forces applied in area? 1 of the deformable body, with another system forces equivalent to and applied it in another area? 2, it will affect the voltages and deformations in the area? that contains? 1 and? 2 and whose size is around the greater of the two areas. c) the hypothesis of local equilibrium. If one body is stationary, then each of its part will also be at rest. d) the hypothesis of a static action forces. All applications forces increase gradually from zero to its final value. e) the hypothesis of initial and final state of equilibrium. Let the beam under the action of the load is in equilibrium. Because displacements are small, it remains in equilibrium. F ? f) the principle of superposition. The final value of the quantity (voltage, deformation, displacement, rotation) as a result of a set of external loads can be obtained as the algebraic sum of the values of these variables, which correspond to different loads that population. F ? F 2 1 F ? 1 ? F 2 1 2 ? =? +? 1 2 g) the principle of hardening. Before loading the body has a certain shape and size. F F 2 1 F 3 F 4 After etching, there is another body shape and size. F F 2 1 F 3 F 4 Perfectly rigid body - consists of particles, distances between not change. Deformable solid - spaces between the particles are change. It is perfectly elastic to a certain degree of loading. —Preceding unsigned comment added by 77.245.12.217 (talk) 20:11, 8 September 2009 (UTC)

First paragraph
I tidied up the first paragraph to improve the grammar and make it a bit more accessible to a general audience. It still needs a bit more work in this regard. Fbsck (talk) 10:18, 13 December 2010 (UTC)

Cut and paste of material into the article
It is not appropriate to cut and paste material from other sources without clarifying that the material is in the public domain or released under an appropriate license. Material also requires proper attribution. --Nuujinn (talk) 20:34, 23 January 2011 (UTC)

Things to improve
Currently the article is long on definitions and short on prose. RJFJR (talk) 03:19, 1 March 2012 (UTC)

Screwy sentence
The article says this


 * "The strength of any material relies on three different types of analytical method: strength, stiffness and stability,"

which has two problems. First, it asserts that a material's strength relies on an analytical method. That is a category error: material strength is a property of the physical world, whereas analytical methods are mental concepts created by and for human reasoning. The second problem with the quoted passage is that it asserts that a material's strength relies (in part) on analysis of strength. That is a mereological error reminiscent of Russell's paradox and the corresponding flaw at the heart of naive set theory; at the very least, it's a circular definition.

I'd fix the offending passage myself, but I ain't no mechanical engineer. So I must resort to recruiting some competent third party to kindly set things aright.PaulTanenbaum (talk) 18:25, 27 June 2012 (UTC)

Strength of Materials vs Solid Mechanics?
I've always been under the impression that Strength of Materials and Solid Mechanics were names that could be used interchangeably. However, Wikipedia has distinct articles on these topics, which do not talk of each other at all, apart from mentioning each other in their respective "See also" sections.

Could someone please add an authentic statement which clarifies the relationship (if any) between these two topics, in at least one of these articles? Yetanotherwriter (talk) 05:27, 11 April 2014 (UTC)


 * I also thought they were different names for the same field (along with Mechanics of Materials and other terms). I propose that Strength of Materials and Solid Mechanics be merged unless someone can clarify the difference between the subjects (preferably a civil engineering expert using cited sources). The ambiguity is frustrating. Jokester251 (talk) 23:38, 23 February 2016 (UTC)