What is Stress: Definition and 1000 Discussions

In linguistics, and particularly phonology, stress or accent is the relative emphasis or prominence given to a certain syllable in a word or to a certain word in a phrase or sentence. That emphasis is typically caused by such properties as increased loudness and vowel length, full articulation of the vowel, and changes in tone. The terms stress and accent are often used synonymously in that context but are sometimes distinguished. For example, when emphasis is produced through pitch alone, it is called pitch accent, and when produced through length alone, it is called quantitative accent. When caused by a combination of various intensified properties, it is called stress accent or dynamic accent; English uses what is called variable stress accent.
Since stress can be realised through a wide range of phonetic properties, such as loudness, vowel length, and pitch (which are also used for other linguistic functions), it is difficult to define stress solely phonetically.
The stress placed on syllables within words is called word stress. Some languages have fixed stress, meaning that the stress on virtually any multisyllable word falls on a particular syllable, such as the penultimate (e.g. Polish) or the first (e.g. Finnish). Other languages, like English and Russian, have lexical stress, where the position of stress in a word is not predictable in that way but lexically encoded. Sometimes more than one level of stress, such as primary stress and secondary stress, may be identified.
Stress is not necessarily a feature of all languages: some, such as French and Mandarin, are sometimes analyzed as lacking lexical stress entirely.
The stress placed on words within sentences is called sentence stress or prosodic stress. That is one of the three components of prosody, along with rhythm and intonation. It includes phrasal stress (the default emphasis of certain words within phrases or clauses), and contrastive stress (used to highlight an item, a word or part of a word, that is given particular focus).

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  1. Tapias5000

    How to calculate the normal stress of a Howe reinforcement?

    This is the structure I already made the calculation of all the bars T = tension and C = compression, these are the results. now I am asked to calculate the normal stress in all the bars but I don't understand where to start, could you tell me how? here is the diagram of the first node but I...
  2. N

    Confidence in FEA stress values?

    Hi all, I’m trying to get a better understanding of ANSYS as I don’t have a lot of experience with it. My question is with respect to a static structural analysis of a solid part: “how can I be reasonably confident that FEA is giving me reasonably accurate stress values?” I’ll analyse a...
  3. FEAnalyst

    Calculating Chain Link Strength: Which Method Should You Use?

    Hi, I am interested in the topic of hand calculations of chain link's strength. I am talking about a regular industrial chain with hanging weight. From what I've read, there are 3 potentially possible approaches: - Lame's problem (circular cross-section has to be replaced with equivalent...
  4. T

    Cauchy's Formula for Stress tensor

    Hello I am reviewing the proof of Cauchy's formula for the stress tensor and surface traction. Without exception, every book I look at gets to the critical point of USING the projection of a triangle onto one of the three orthogonal planes. However, I have never seen this proven. I have...
  5. FEAnalyst

    Hertz contact stress with prescribed displacement

    Hi, one can easily find formulas for Hertz contact stress in various cases (two spheres, two cylinders and so on) when force is applied to one of the bodies. But how to get the equivalents of those formulas when prescribed displacement is used instead of stress ? For example, I’ve found this...
  6. S

    B Question about stress - strain graph and definition of hardness

    This is from my notes: Point D is called ultimate tensile strength and defined as highest possible within this material. So it means that point D should be at the highest point of the graph (more like absolute maximum in math)? Because it seems that from the graph point D is not at maximum...
  7. freddie_mclair

    Calculate the residual stress on a beam after bending

    Hello everyone, I hope you can give me hand with what I will present. I have a beam with cross-section shown below. I considered a simple linear hardening model for predicting the stress and strain developed by bending the beam on the radius ##R_0## around the y-axis, where: The strain...
  8. grotiare

    Engineering Question about max stress on circular cross section with two moments

    I couldn't fit in the title, but this is with a hollow circular cross section So currently I am trying to figure what occurs when two, perpendicular bending moments are applied to a hollow circular cross section (one about the z axis, and the other about y). I know that if I was dealing with a...
  9. Rob B

    Shear stress damage due to thermal gradient

    I'm trying to use my rudimentary understanding of material physics to understand a simple problem, and am getting stuck - I hope you can help! My idealized case involves a sheet of infinite extent in length and width direction, to which a linear thermal gradient in the depth dimension is...
  10. R

    Choosing correct steel beam for a span

    I have a weight of 30,000 lbs distributed across a span of 100' and supported at the ends. If I have 3 beams to support this load, each beam would then need to hold 10,000 lbs, and with a F.S of 1.6 each beam would need to hold 16,000 lbs. If I assume my max deflection at 1", then I can find the...
  11. B

    Frame indifference and stress tensor in Newtonian fluids

    During lecture today, we were given the constitutive equation for the Newtonian fluids, i.e. ##T= - \pi I + 2 \mu D## where ##D=\frac{L + L^T}{2}## is the symmetric part of the velocity gradient ##L##. Dimensionally speaking, this makes sense to me: indeed the units are the one of a pressure...
  12. B

    I Divergence of first Piola-Kirchoff stress tensor

    Hi everyone, studying the bending of an incompressible elastic block of Neo-Hookean material, one finds out the first Piola-Kirchoff stress tensor as at page 182 (equation 5.93) where $e_r = cos(\theta)e_1 + \sin(\theta)e_2$ and $e_{\theta} = -sin(\theta)e_1 + \cos(\theta)e_2$ How is the...
  13. wrobel

    A Stress Tensor: Definition, Ideas & Discussion

    Inspired by the closed thread about pressure:) Here is some of my fantasies about a definition of the stress tensor. Nothing here claims to be a correct theory but just as a matter for discussion.
  14. L

    I'm trying to understand compressive strength and Euler stress for columns

    A cloumn has a compressive strength of 220MPa, but its Euler yeild stress is 350MPa. its compressive strength is less than its euler stress. what does this mean?
  15. D

    I Contracting the stress energy tensor

    I am trying to understand the scalar form of the Einstein field equations. I know that you can contract the stress-energy tensor using the metric. And for a perfect fluid model, this turns out to be the energy density summed with the pressure. This also gives the Ricci scalar. However, you can...
  16. B

    Invariants of the stress tensor (von Mises yield criterion)

    Hello all, I am trying to understand the von Mises yield criterion and stumbled across two equations for the second stress invariant. Although the only difference is a difference in signs (negative and positive), it has been bothering me. Attached are the two versions. Which one is correct and...
  17. F

    Plane stress concept with a fixed end

    Under plane stress (z direction perpendicular to the plane), there shouldn’t be any z stress component. Then if one end of the 2D model is fixed, does that mean the displacement on that fixed boundary is completely zero (u=v=w=0), but that will generally violate the stress component along z being 0.
  18. Krokodrile

    Engineering Determine the stress in each of these sections of tile

    For this problem the teacher explains the procedure for made it. I am sure that I am fine with my solution, but hours ago many teammate thay had different results...and now I am not sure.
  19. H

    How to calculate the maximum stress in a rib of a complex construction

    A Construction is stiffened by a bottemplate with welded ribs. A flange welded to the inletpipe is bolted at the botomplate. I want to simulate the current situation. Therfore I need a handcalculation of the stresses in the ribs of the constuction. The forces and moments are working in the worst...
  20. K

    Understanding Principle Stress Planes: Exploring Shear Forces and Rotation

    All the materials that I have been reading, it says that when the element is rotated to a θ, this will be called the principle stress plane with no shear force acting on it. but visually when you rotate the element, there will be a shear force acting parallel to the plane. I am very confused...
  21. L

    Engineering Understanding Shear Stress Theories: Moors Circle & McGraw Hill

    Hello:) Our homework is done through mcgraw hill connect. I am able to see the solution to the problem and it contradicts what the book and powerpoint says. according to the powerpoint given by my professor, moors circle, sigma1 = Sy or yield strength. Powerpoint also states that sigma(x) is...
  22. Y

    Is a solid cylinder considered thick or thin?

    I have a solid cylinder of diameter 40mm and length 14mm and I have used plane stress approximations in my calculations so far. I know for to assume a thin walled cylinder/tube the wall thickness needs to be less than 1/20 of tube or cylinder diameter. However, what I have found so far is that...
  23. FEAnalyst

    Quick return mechanism stress analysis

    Hi, I wonder how to approach stress analysis of quick return mechanism used in shaper machines (see the diagram below): The first issue is: which moment in the working process of this mechanism should be used for analysis (when will the mechanism experience largest loads)? So far I assumed...
  24. E

    What is the relationship between force lines and the stress tensor field?

    Force lines method is used in Solid Mechanics for visualization of internal forces in a deformed body. A force line represents graphically the internal force acting within a body across imaginary internal surfaces. The force lines show the maximal internal forces and their directions. But...
  25. pipeguy

    A Stress point calculation some practical help

    https://www.physicsforums.com/attachments/273785 What are the possible materials (beams, H-profiles) etc that can be used to withstand the pressure of the whole system if there are 12 tonnes of wheat in the pipe at all times? How you would make this system work? There always has to be an angle...
  26. baldbrain

    A basic doubt about stress and strain

    While introducing tensile stress, we're shown a bar fixed at a support being subjected to a force in the axial direction at the opposite end. Then, since the bar is in translational equilibrium, we say that internal forces must balance it out, and this internal resistance per unit area is known...
  27. G

    Shear stress distribution for a tapered beam

    I am reading a journal article from Balduzzi about shear stress recover on tapered beams. I can not get the exact constants he gets and I am stumped. Above is solving for differential piece of the beam. Equations 16-18 are the ones I am trying to calculate. I attached my work and the...
  28. Q

    Normal Stress in Rods Experiencing Temperature Changes

    Now here is the part where I'm sort of stumped myself: Could someone let me know if my reasoning is valid? The professor explained it during office hours and all I got out of that was that something cancels out and the answer is 0.
  29. D

    Biophysics Q: Impact of stiffness (Young's modulus) on stress failure

    Hi. I'm a physician trying to understand the micromechanics of lung injury due to overdistension. The basic idea is that overstretching of the plasma membrane of the lung epithelial cell causes "stress failure" --> i.e. plasma membrane rupture --> cell death. The concepts of stress, strain, and...
  30. FEAnalyst

    Fatigue life of a simple beam

    Hi, some time ago I wondered if it's possible to calculate fatigue life (number of cycles to failure) for complex models analytically, based on static FEA results: https://www.physicsforums.com/threads/fatigue-life-hand-calculations-based-on-static-fea-results.994264/ Unfortunately, it seems...
  31. FEAnalyst

    Capped pressure vessel - strength and stability

    Hi, in mechanics of materials books one may easily find fomulas for stress and strain in thin- and thick-walled cylindrical pressure vessels subjected to internal pressure. However, it is assumed that they are open. So what are the formulas for stress and strain in capped vessels (with flat or...
  32. FEAnalyst

    Maximum shear stress in an assymetric cross-section

    Hi, the formula for average shear stress in cross-section due to bending is simple: $$\tau=\frac{V}{A}$$ There’s also a formula for maximum shear stress in cross-section: $$\tau_{max}=\frac{VQ}{Ib}$$ But, from what I know, this equation is limited to symmetric cross-sections (rectangular, I...
  33. Glenn Rowe

    Electromagnetic stress tensor from pressure and tension

    I'm puzzling over Exercise 1.14 in Thorne & Blandford's Modern Classical Physics. We are given that an electric field ##\boldsymbol{E}## exerts a pressure ## \epsilon_{0}\boldsymbol{E}^{2}/2## orthogonal to itself and a tension of the same magnitude along itself. (The magnetic field does the...
  34. C

    A How are the thermal expansion of a solid and the stress tensor related?

    My idea is this: tensor stress is directly related to the internal pressure of a solid. That is to the force that the neighboring atoms exert each other in relation to a unit of surface. When I heat a solid we can have the phenomenon of thermal expansion: this is connected to the fact that a...
  35. G

    Modeling Stress in Simple Objects: Easy Software Options?

    I am trying to model stress in simple objects such as a disk, a cube, a rectangular prism or a solid ball under their own weight or additional point mass weight on top to demonstrate such material response to students. I understand the usual process is to set up Mesh, boundary condition, and...
  36. E

    Understanding Stress in Pipe Walls: Impact of Internal Air Pressure

    Consider a pipe. The pipe is not crushed by the air pressure because the same air pressure is acting from inside the pipe. But this means that the material of the pipe is being compressed on both sides by some air pressure. So is it correct to say that the through-thickness stress in the pipe...
  37. person123

    I Normal Stress Vectors: Sketch 1 vs Sketch 2

    Let's say you have a material element with normal and shear stress. These stresses were computed using stress transformation. When the material deforms, should the normal stress vectors remain normal to the surface (sketch 1) or parallel to the other surface (sketch 2)? Which would be more...
  38. person123

    I Stresses Caused By Deformation For Bending

    Hi. Say you apply a moment on a beam and bend it into an arch. If you take a free body diagram of a section of the beam you would need normal stresses in the radial direction to balance the forces: I have never seen this brought up before though -- is it correct logic? Also, is this sort of...
  39. Rahulx084

    Some questions about Friction in fluid flow

    I have few conceptual doubts in fluid mechanics. Here is the one I will ask first. I want to understand the force direction acting on the solid liq interface during fluid flow, Let's say a fluid is flowing in a pipe. Now the fluid applies a shear stress at the walls of pipe in the direction of...
  40. H

    Effect of initial stress on the natural frequency of vibration

    Hello all, We might have observed that by tightening a string of a musical instrument, the natural frequency of the string changes. But I can not describe this phenomenon by the theory of linear elasticity. Also if we simulate the vibration of a bar with the help of structural software tools...
  41. B

    Engineering Angle of twist and Shear stress in a shaft

    Hello, I have attempted the question below. I think i have correctly completed the question. Could anyone see if i have gone wrong? As trying to learn this. I am just worried about the units m to mm. Also the answer being correct, 917.6Gpa. I was unsure what units to use on the answer...
  42. B

    What is the shear stress in a lap joint with a double lap configuration?

    Here is a MCQ which I'm struggling to answer The option with a red dot is the answer I chosen and think is right I know that stress is equal to force/area Area i.e. the cross sectional area of a circle is (pi*d2)/4 Looking at the simple lap joint, force is simple P netwons hence stress is...
  43. B

    Interpreting Stress-Strain Graph: Which Material Has the Highest Ductility?

    This is a quick multiple choice question in which I need to interpret the graph and see which statement is true This is what I have found from looking at the graph I know that strength is determined by the maximum stress a material can withstand in its elastic region. And toughness is the...
  44. P

    Calculate the maximum vertical point force P that this beam can sustain

    A simply-supported steel beam with a vertical point force P is shown in Fig. 2(a). A cross-section of the beam, which is composed of two identical C-shaped members bolted back-to-back, is shown in Fig. 2(b). Both C-shaped members have a uniform thickness of 1 cm. Pairs of bolts are located at a...
  45. person123

    Lines of Stress in a Material

    I was initially curious by the fact that streamlines around a circle appear the same as the lines of stress around a hole: I understand that streamlines are the contour lines of the stream function ##\psi## which satisfies the Laplace equation. I was wondering there is a related function for...
  46. ANSAN

    Need the Permissible Stress (Shear & Bending) values of various materials

    Hi all, i need Permissible stress (Shear & Bending) values of various materials that is used for shaft design, as like below. Is there any software or excel sheet. kindly let know.
  47. G

    Out-of-plane bending stress on an I-beam

    I know the out of plane bending stress equation for a curved I beam but I am trying to figure out where it came from. sigmaR = tFlange * sigmaNormal/(radius of curvature)
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