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#solidmechanics — Public Fediverse posts

Live and recent posts from across the Fediverse tagged #solidmechanics, aggregated by home.social.

  1. Fluids Can Fracture

    Fracture is a sudden, brittle breaking-apart that we generally associate with solid materials that get stressed too far. Some viscoelastic, non-Newtonian fluids have been known to fracture, but that was generally thought to be unusual. But a recent study turns that idea on its head, revealing that even simple, albeit highly viscous, liquids can fracture.

    A viscous hydrocarbon fluid gets stretched at 100 mm/s, drawing it into a thinning shape.

    When you stretch a liquid, the general expectation is what you see above: the liquid gets drawn into an ever thinner shape. But researchers found that–when stretched quickly–that same simple hydrocarbon liquid cracked open:

    A viscous hydrocarbon fluid gets stretched at 300 mm/s, causing it to fracture like a solid.

    There’s even an audible snap, which you can hear in the video below. The results were so surprising that they repeated the experiment several times and with different viscous (but Newtonian) liquids. The results held. When the liquids were pulled to a critical stress, they audibly snapped and fractured like a solid.

    The next question, of course, is why this happens. The authors suspect (but have yet to show) that cavitation may be at play in the initiation of the crack that separates the liquid in two. (Image, video, and research credit: T. Lima et al.; via Gizmodo)

    https://www.youtube.com/watch?v=i5TQegTyCvc

    #fluidDynamics #fracture #newtonianFluids #physics #science #solidMechanics #viscousFlow
  2. Fluids Can Fracture

    Fracture is a sudden, brittle breaking-apart that we generally associate with solid materials that get stressed too far. Some viscoelastic, non-Newtonian fluids have been known to fracture, but that was generally thought to be unusual. But a recent study turns that idea on its head, revealing that even simple, albeit highly viscous, liquids can fracture.

    A viscous hydrocarbon fluid gets stretched at 100 mm/s, drawing it into a thinning shape.

    When you stretch a liquid, the general expectation is what you see above: the liquid gets drawn into an ever thinner shape. But researchers found that–when stretched quickly–that same simple hydrocarbon liquid cracked open:

    A viscous hydrocarbon fluid gets stretched at 300 mm/s, causing it to fracture like a solid.

    There’s even an audible snap, which you can hear in the video below. The results were so surprising that they repeated the experiment several times and with different viscous (but Newtonian) liquids. The results held. When the liquids were pulled to a critical stress, they audibly snapped and fractured like a solid.

    The next question, of course, is why this happens. The authors suspect (but have yet to show) that cavitation may be at play in the initiation of the crack that separates the liquid in two. (Image, video, and research credit: T. Lima et al.; via Gizmodo)

    https://www.youtube.com/watch?v=i5TQegTyCvc

    #fluidDynamics #fracture #newtonianFluids #physics #science #solidMechanics #viscousFlow
  3. Fluids Can Fracture

    Fracture is a sudden, brittle breaking-apart that we generally associate with solid materials that get stressed too far. Some viscoelastic, non-Newtonian fluids have been known to fracture, but that was generally thought to be unusual. But a recent study turns that idea on its head, revealing that even simple, albeit highly viscous, liquids can fracture.

    A viscous hydrocarbon fluid gets stretched at 100 mm/s, drawing it into a thinning shape.

    When you stretch a liquid, the general expectation is what you see above: the liquid gets drawn into an ever thinner shape. But researchers found that–when stretched quickly–that same simple hydrocarbon liquid cracked open:

    A viscous hydrocarbon fluid gets stretched at 300 mm/s, causing it to fracture like a solid.

    There’s even an audible snap, which you can hear in the video below. The results were so surprising that they repeated the experiment several times and with different viscous (but Newtonian) liquids. The results held. When the liquids were pulled to a critical stress, they audibly snapped and fractured like a solid.

    The next question, of course, is why this happens. The authors suspect (but have yet to show) that cavitation may be at play in the initiation of the crack that separates the liquid in two. (Image, video, and research credit: T. Lima et al.; via Gizmodo)

    https://www.youtube.com/watch?v=i5TQegTyCvc

    #fluidDynamics #fracture #newtonianFluids #physics #science #solidMechanics #viscousFlow
  4. Fluids Can Fracture

    Fracture is a sudden, brittle breaking-apart that we generally associate with solid materials that get stressed too far. Some viscoelastic, non-Newtonian fluids have been known to fracture, but that was generally thought to be unusual. But a recent study turns that idea on its head, revealing that even simple, albeit highly viscous, liquids can fracture.

    A viscous hydrocarbon fluid gets stretched at 100 mm/s, drawing it into a thinning shape.

    When you stretch a liquid, the general expectation is what you see above: the liquid gets drawn into an ever thinner shape. But researchers found that–when stretched quickly–that same simple hydrocarbon liquid cracked open:

    A viscous hydrocarbon fluid gets stretched at 300 mm/s, causing it to fracture like a solid.

    There’s even an audible snap, which you can hear in the video below. The results were so surprising that they repeated the experiment several times and with different viscous (but Newtonian) liquids. The results held. When the liquids were pulled to a critical stress, they audibly snapped and fractured like a solid.

    The next question, of course, is why this happens. The authors suspect (but have yet to show) that cavitation may be at play in the initiation of the crack that separates the liquid in two. (Image, video, and research credit: T. Lima et al.; via Gizmodo)

    https://www.youtube.com/watch?v=i5TQegTyCvc

    #fluidDynamics #fracture #newtonianFluids #physics #science #solidMechanics #viscousFlow
  5. Fluids Can Fracture

    Fracture is a sudden, brittle breaking-apart that we generally associate with solid materials that get stressed too far. Some viscoelastic, non-Newtonian fluids have been known to fracture, but that was generally thought to be unusual. But a recent study turns that idea on its head, revealing that even simple, albeit highly viscous, liquids can fracture.

    A viscous hydrocarbon fluid gets stretched at 100 mm/s, drawing it into a thinning shape.

    When you stretch a liquid, the general expectation is what you see above: the liquid gets drawn into an ever thinner shape. But researchers found that–when stretched quickly–that same simple hydrocarbon liquid cracked open:

    A viscous hydrocarbon fluid gets stretched at 300 mm/s, causing it to fracture like a solid.

    There’s even an audible snap, which you can hear in the video below. The results were so surprising that they repeated the experiment several times and with different viscous (but Newtonian) liquids. The results held. When the liquids were pulled to a critical stress, they audibly snapped and fractured like a solid.

    The next question, of course, is why this happens. The authors suspect (but have yet to show) that cavitation may be at play in the initiation of the crack that separates the liquid in two. (Image, video, and research credit: T. Lima et al.; via Gizmodo)

    https://www.youtube.com/watch?v=i5TQegTyCvc

    #fluidDynamics #fracture #newtonianFluids #physics #science #solidMechanics #viscousFlow
  6. Rolling Down Soft Surfaces

    Place a rigid ball on a hard vertical surface, and it will free fall. Stick a liquid drop there, and it will slide down. But researchers discovered that with a soft sphere and a soft surface, it’s possible to roll down a vertical wall. The effect requires just the right level of squishiness for both the wall and sphere, but when conditions are right, the 1-millimeter radius sphere rolls (with a little slipping) down the wall.

    Rolling requires torque, something that’s usually lacking on a vertical surface. But the team found that their soft spheres got the torque needed to roll from their asymmetric contact with the surface. More of the sphere contacted above its centerline than below it. The researchers compared the way the sphere contacted the surface to a crack opening (at the back of the sphere) and a crack closing (at the front of the sphere). That asymmetry creates just enough torque to roll the sphere slowly. The team hopes their discovery opens up new possibilities for soft robots to climb and descend vertical surfaces. (Image and research credit: S. Mitra et al.; via Gizmodo)

    #adhesion #fluidDynamics #physics #science #slip #softMatter #solidMechanics

  7. Chaotic Hose Instability

    Steve Mould is back with another video looking at wild fluid behaviors. This time he’s considering hose instabilities like the one that makes a water-carrying hose beyond a certain length to whip wildly back and forth. He tries to track down the reasoning for these flexible hoses snapping and whipping. In truth, both the hoses and the wind dancers do their thing due to interactions between the elasticity of the hose and the fluid dynamics of the flows within. These applications are ripe for a few control volume thought experiments. (Video and image credit: S. Mould)

    #chaos #elasticity #fluidDynamics #physics #science #solidMechanics

  8. Ultra-Soft Solids Flow By Turning Inside Out

    Can a solid flow? What would that even look like? Researchers explored these questions with an ultra-soft gel (think 100,000 times softer than a gummy bear) pumped through a ring-shaped annular pipe. Despite its elasticity — that tendency to return to an original shape that distinguishes solids from fluids — the gel does flow. But after a short distance, furrows form and grow along the gel’s leading edge.

    Front view of an ultra-soft solid flowing through an annular pipe. The furrows forming along the face of the gel are places where the gel is essentially turning itself inside out.

    Since the gel alongside the pipe’s walls can’t slide due to friction, the gel flows by essentially turning itself inside out. Inner portions of the gel flow forward and then split off toward one of the walls as they reach the leading edge. This eversion builds up lots of internal stress in the gel, and furrowing — much like crumpling a sheet of paper — relieves that stress. (Image and research credit: J. Hwang et al.; via APS News)

    #flowVisualization #fluidDynamics #instability #physics #pipeFlow #science #softMatter #solidMechanics #stress

  9. Ultra-Soft Solids Flow By Turning Inside Out

    Can a solid flow? What would that even look like? Researchers explored these questions with an ultra-soft gel (think 100,000 times softer than a gummy bear) pumped through a ring-shaped annular pipe. Despite its elasticity — that tendency to return to an original shape that distinguishes solids from fluids — the gel does flow. But after a short distance, furrows form and grow along the gel’s leading edge.

    Front view of an ultra-soft solid flowing through an annular pipe. The furrows forming along the face of the gel are places where the gel is essentially turning itself inside out.

    Since the gel alongside the pipe’s walls can’t slide due to friction, the gel flows by essentially turning itself inside out. Inner portions of the gel flow forward and then split off toward one of the walls as they reach the leading edge. This eversion builds up lots of internal stress in the gel, and furrowing — much like crumpling a sheet of paper — relieves that stress. (Image and research credit: J. Hwang et al.; via APS News)

    #flowVisualization #fluidDynamics #instability #physics #pipeFlow #science #softMatter #solidMechanics #stress

  10. Ultra-Soft Solids Flow By Turning Inside Out

    Can a solid flow? What would that even look like? Researchers explored these questions with an ultra-soft gel (think 100,000 times softer than a gummy bear) pumped through a ring-shaped annular pipe. Despite its elasticity — that tendency to return to an original shape that distinguishes solids from fluids — the gel does flow. But after a short distance, furrows form and grow along the gel’s leading edge.

    Front view of an ultra-soft solid flowing through an annular pipe. The furrows forming along the face of the gel are places where the gel is essentially turning itself inside out.

    Since the gel alongside the pipe’s walls can’t slide due to friction, the gel flows by essentially turning itself inside out. Inner portions of the gel flow forward and then split off toward one of the walls as they reach the leading edge. This eversion builds up lots of internal stress in the gel, and furrowing — much like crumpling a sheet of paper — relieves that stress. (Image and research credit: J. Hwang et al.; via APS News)

    #flowVisualization #fluidDynamics #instability #physics #pipeFlow #science #softMatter #solidMechanics #stress

  11. Ultra-Soft Solids Flow By Turning Inside Out

    Can a solid flow? What would that even look like? Researchers explored these questions with an ultra-soft gel (think 100,000 times softer than a gummy bear) pumped through a ring-shaped annular pipe. Despite its elasticity — that tendency to return to an original shape that distinguishes solids from fluids — the gel does flow. But after a short distance, furrows form and grow along the gel’s leading edge.

    Front view of an ultra-soft solid flowing through an annular pipe. The furrows forming along the face of the gel are places where the gel is essentially turning itself inside out.

    Since the gel alongside the pipe’s walls can’t slide due to friction, the gel flows by essentially turning itself inside out. Inner portions of the gel flow forward and then split off toward one of the walls as they reach the leading edge. This eversion builds up lots of internal stress in the gel, and furrowing — much like crumpling a sheet of paper — relieves that stress. (Image and research credit: J. Hwang et al.; via APS News)

    #flowVisualization #fluidDynamics #instability #physics #pipeFlow #science #softMatter #solidMechanics #stress

  12. Ultra-Soft Solids Flow By Turning Inside Out

    Can a solid flow? What would that even look like? Researchers explored these questions with an ultra-soft gel (think 100,000 times softer than a gummy bear) pumped through a ring-shaped annular pipe. Despite its elasticity — that tendency to return to an original shape that distinguishes solids from fluids — the gel does flow. But after a short distance, furrows form and grow along the gel’s leading edge.

    Front view of an ultra-soft solid flowing through an annular pipe. The furrows forming along the face of the gel are places where the gel is essentially turning itself inside out.

    Since the gel alongside the pipe’s walls can’t slide due to friction, the gel flows by essentially turning itself inside out. Inner portions of the gel flow forward and then split off toward one of the walls as they reach the leading edge. This eversion builds up lots of internal stress in the gel, and furrowing — much like crumpling a sheet of paper — relieves that stress. (Image and research credit: J. Hwang et al.; via APS News)

    #flowVisualization #fluidDynamics #instability #physics #pipeFlow #science #softMatter #solidMechanics #stress

  13. Congratulations to Sébastien Court, Associate Professor at the Department of #Mathematics and the DiSC of @uniinnsbruck, for receiving the prestigious Research Award of the Stiftung Südtiroler Sparkasse for his recent, outstanding research papers with contributions to the theory of partial differential equations, particularly in the field of solid and fluid mechanics: uibk.ac.at/en/disc/news/resear

    #SolidMechanics #FluidMechanics

  14. #SPHERIC2025 will be in #Barcelona
    spheric2025.upc.edu/

    It will be the first #SPHERIC #conference to break from the "classic" SPHERIC International Workshop format that was also employed for the SPHERIC 2022 I organized in Catania, and closer to other more traditional conferences (hence also the change in name, to SPHERIC World Conference).

    1/

    #SPH #CFD #SolidMechanics #AstroPhysics #ParticleMethods

  15. These days glass screens travel with us everywhere, and they can take some big hits on the way. Manufacturers have made tougher glass, but they continue to look for ways to protect our screens. Recently, a study suggested that non-Newtonian fluids are well-suited to the task.

    The team explored the physics of sandwiching a layer of fluid between a glass top layer and an LCD screen bottom layer, mimicking structures found in electronic devices. Through simulation, they searched for the fluid characteristics that would best minimize the forces felt by the solid layers during an impact. They found that shear-thinning fluids — fluids that, like paint or shampoo, get runnier when they’re deformed — provided the best protection. Having the impact energy go into reducing the local viscosity of the fluid stretches the length of time the impact affects the glass, which lowers the bending forces on it and helps avoid breakage. (Image credit: G. Rosenke; research credit: J. Richards et al.; via Physics World)

    https://fyfluiddynamics.com/2024/05/saving-screens-with-shear-thinning-fluids/

    #engineering #fluidDynamics #nonNewtonianFluids #numericalSimulation #physics #science #shearThinning #solidMechanics #viscosity

  16. These days glass screens travel with us everywhere, and they can take some big hits on the way. Manufacturers have made tougher glass, but they continue to look for ways to protect our screens. Recently, a study suggested that non-Newtonian fluids are well-suited to the task.

    The team explored the physics of sandwiching a layer of fluid between a glass top layer and an LCD screen bottom layer, mimicking structures found in electronic devices. Through simulation, they searched for the fluid characteristics that would best minimize the forces felt by the solid layers during an impact. They found that shear-thinning fluids — fluids that, like paint or shampoo, get runnier when they’re deformed — provided the best protection. Having the impact energy go into reducing the local viscosity of the fluid stretches the length of time the impact affects the glass, which lowers the bending forces on it and helps avoid breakage. (Image credit: G. Rosenke; research credit: J. Richards et al.; via Physics World)

    https://fyfluiddynamics.com/2024/05/saving-screens-with-shear-thinning-fluids/

    #engineering #fluidDynamics #nonNewtonianFluids #numericalSimulation #physics #science #shearThinning #solidMechanics #viscosity

  17. Soft materials tend to be sticky, and once they’re adhered to a surface, they’re often harder to remove than they were to attach — think of Scotch tape stuck to a desk. This difficulty separating sticky things — known as adhesion hysteresis — has been attributed to various causes, like energy lost to viscoelasticity or age-related chemical bonding. But a new study shows that both those explanations are unnecessary.

    Instead, the difficult removal comes from the way two surfaces separate in fits and starts. No two surfaces are perfectly smooth, and soft surfaces are able to conform to all the nooks and crannies of their partner surface. That molding results in a lot of surface contact, all of which must break for the materials to detach. That peeling doesn’t take place smoothly. Instead, the two surfaces part a little at a time in discrete jumps, as shown in the image above. The colors in the illustration show how much energy is dissipated in each jump, with darker colors indicating higher energy. The team found that this stick-slip mechanism is enough to account for the struggles we have un-sticking objects. They’re now looking at how water affects these narrow meeting places between sticky surfaces. (Image and research credit: A. Sanner et al.; via Physics World)

    https://fyfluiddynamics.com/2024/05/unsticking-in-jumps/

    #adhesion #fluidDynamics #physics #science #solidMechanics #stickSlip #surfaceRoughness

  18. To fly stably, parachutes need to deform and allow some air to pass through their canopy. In this video, researchers investigate kirigimi parachutes, inspired by a form of paper art that uses cuts to create three-dimensional shapes. After laser-cutting, these disks are dropped — or placed in a wind tunnel — to observe how they “fly” at different speeds. Sometimes they flutter or bend; other shapes elongate in the flow. (Video and image credit: D. Lamoureux et al.; via GoSM)

    https://fyfluiddynamics.com/2024/05/kirigami-parachutes/

    #2024gosm #drag #fluidDynamics #parachutes #physics #science #solidMechanics

  19. doodling on my #whiteboard 😋

    and tried to remember some formulas from my mechanical-engineering study xD

    drawing on whiteboards is still so much fun, I really want to improve this.

    #art #mastoart #solidmechanics

  20. In #SolidMechanics, #stress has some counter-intuitive properties, particularly when you rotate the coordinate system. The values of normal and shear stress transform according to the rules of #second-order #tensors, which is a step above #vectors (first-order tensors).

    #Mechanics #Mathematics #Engineering