Recent content by Dr Bwts

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    Force required to compress or extend a helical spring.

    Also depends on how the spring is coiled. If it is tightly coiled then compression is more likely to cause buckling than axial compression. In which case a simple Hooke's law assumtion will be invalid.
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    Plate four points bending equation for a plate

    Nice reference thanks.
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    Plate four points bending equation for a plate

    Well Roark's is definately the go to book but like PhantomJay I don't remember seeing that in there but you never know. My solution would be use FEA. I know you won't get an analytical solution but you may be able to validate it via a simple experiment.
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    FEA: Stiffness Matrix for Beam Element

    Agreed Well yes and no really. It does help in a broader sense by introducing students to the idea that you can choose a coordinate system to suit your problem. Its suprising how many students don't realize this.
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    Transformation matrix from global to loca frame

    Do you have the transform matrix for the first atom to the world frame? I would have thought that if you have the end atoms position in terms of the first atom's coordinate system, then you could just apply the transformation matrix for the first atom to the world frame.
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    What causes rotation, a coupe or a moment?

    A couple is a special case of a moment when 2 equal moments act in opposite direction about a pivot. The resolving of forces is (in my opinion anyway) a useful mathematical tool but in real life such things as the material constituent behaviour come into play and things get much more...
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    FEA: Stiffness Matrix for Beam Element

    Both, although the convention when teaching beam deflection problems is that 'downward' deflection is taken as positive. (I think this convention comes from Naval engineering can't remember now though) Its just a matter of how the reference coordinate system is defined.
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    Mechatronics = Mechanical engineer who knows some electronics?

    My first degree was in Mechatronics it was mostly geared towards control systems i.e. electronic systems controlling mechanical systems.
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    What is the Role of Resistivity in Determining the Purity of Solvents?

    Thermoluminescence questions... Hi, First off apologies if this is in the wrong sub-forum. I was given the following two papers to read... Thermoluminescence of ultra-high dilutions of lithium chloride and sodium chloride. Rey, L. Physica A 323 (2003) 67–74. Thermoluminescence in...
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    Aligning a matrix with its eigen vectors and other questions?

    OK panic over I just divide the aligned matrix by its trace. Thanks for your time.
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    Aligning a matrix with its eigen vectors and other questions?

    Thanks for the reply. Once the matrix (A) has been transformed as above how can I scale it such that, trace(A)=1 ?
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    Aligning a matrix with its eigen vectors and other questions?

    Hi, I have a square symmetrical matrix A (ugly I know) 321.1115, -57.5311, -33.9206 -57.5311, 296.7836, 10.8958 -33.9206, 10.8958, 382.1050 which has the eigen values, 248.8034 341.6551 409.5415 Am I right in saying that A...
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    Are spheres isotropic and cubes anisotropic?

    OK thanks chiron that has been very helpful
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    Are spheres isotropic and cubes anisotropic?

    Orthotropic - multually perpendicular planes of symmetry (a particular case of anisotropy)
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    Are spheres isotropic and cubes anisotropic?

    Thanks for the reply. So just so I'm clear, in the case of the cube I would get a distribution that would be orthotropic?
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