Element Definition and 881 Threads

Hi, I'm facing a real-life problem and I don't what specific mathematics topic it's related to. Homework Statement I know the value of the components of a vector field in three points of space and I have to find the flux of this vector field through the surface defined by those...

while working with ansys classic, while adding link element 2D spar is not available in the list,do i need to install it additionally? if yes how? or otherwise what can i do?

Homework Statement The area element of a sphere in spherical coordinates is given as following dA = r^2 \sin(\phi)\; d \theta \; d \phi using the notation in the following figure: However, while going through some E&M books I ran into the following notation Surface \; Area = r^2 \...

So Reynold's transport theorem states that \frac{\mathrm d}{\mathrm d t} \int_{V(t)} f \; \mathrm d V = \int_{V(t)} \partial_t f \; \mathrm d V + \int_{V(t)} \nabla \cdot \left( f \mathbf v \right) \; \mathrm d V. Now I would expect (on basis of conceptual reasoning) that if I were to apply...

\inthi all, I need just little bit of confirmation about what I'm doing. Normally I know how the stiffness matrix is composed for 2 node frame element in 3D space. which creates 12x12 matrix for that element, if there is also thermal loading on frame element additional...

In one of the early chapters of Gravity by Hartle, he is developing the line element on a sphere in preparation for developing the concept of a spacetime interval. Whilst finishing up the proof Hartle sort of implicitly says that if two lines are orthogonal the line element connecting two points...

Hi, If I have a vector c = [ a , 1 ]T where the element a is a vector. If I multiply c by its transpose: cTc is this defined? How do I calculate the a*a? Matrix multiplication rules would say that a * a is undefined because it is a nx1 matrix multiplied by a nx1 matrix. Or is the...

Hi all. I would like to do a finite element simulation of a coil in a time-varying magnetic field, to see how much current is induced in the coil, and also to see how the coil itself affects its surroundings. Now my question is, how do I model a coil with several thousand turns in a practical...

if I have square matrix A whose decimal elements a_{i,j} = \frac{v_i}{v_j} how do I find (or approximate) the vector that would produce the matrix elements. what's a good way to do that? i guess you can scale the vector however you want and it'll still produce the same matrix.. thanks.

I need to design a voltage doubler that takes in 115V-50Hz a.c. and produces a doubled voltage output of 230V dc. I am using this circuit: I need help in the mathematics part: i) How do I find the optimum value of capacitance? (Using high capacitance values reduces ripples; but can...

Hi all. In most of our analysis of continuous systems ex: in fluid mechanics, solid mechanics etc. we consider a differential element(infinitesimally small element) and obtain the differential equations that govern the phenomenon. But why do we consider a differential element? What is it's...

I am in trouble… I am a master student (first year) in theoretical particle physics and I have been working for several months on the calculation of the total cross-section at leading order for the process: u + \overline{d} \rightarrow W^{+} + \gamma I performed the whole calculation by...

Hi, I'll cut to the chase: I've been designing a project that uses a series of MCUs and such, in order to control a series of systems. The device is ment to run from a standard 120 V wall outlet, has a few motor controls, a piston control, but problematically also needs a heating element that...

Homework Statement Let a and b be elements of a group,with a^2=e , b^6=e and a.b=b^4.a find its order and express its inverse in form of a^m.b^n Homework Equations The Attempt at a Solution (ab)^2=(ab)(ab)=(ab)(b^4.a)=a(b^5)a (ab)^3=a(b^5)a(ab)=a(b^5)(a^2)b=a(b^6)=ae=a it...

http://news.yahoo.com/livermorium-flerovium-join-periodic-table-names-213303266.html http://phys.org/news/2012-05-livermorium-flerovium-periodic-table-elements.html http://www.webelements.com/flerovium/, Fl http://www.webelements.com/livermorium/, Lv

Structural Analysis-Writing Finite Element Code, Dear all, I have written a code ( in fact it is a software) for 3D finite element structural analysis. While developing the code I found that assembling global stiffness matrix is quite complicated. The complication is even more when we...

Hi All, I have this clarification, if I have a resistor element of any value and if the physical length of the resistor is say L. Does the resistance of the element increases from 0 at the beginning to R at the end of the resistive element that is L, or it is the average, or it is located at...

I am really stuck with how to prove that the only element in Sn (with n>=3) commuting with all the other elements of this group is the identity permutation id. I have no idea what I am supposed to do with it, i know why S3 has only one element that commutes but i don't know how to prove it...

I have gone through Beam Element analysis in several books on FEA. 80% of books have a particular Stiffness matrix, while a very small number of books have a matrix which is subtly different in sign. http://www.flickr.com/photos/66943862@N06/7195680680/in/photostream/lightbox Most books have...

Let \begin{equation*} A=% \begin{bmatrix} 0 & 1 & \cdots & n-1 & n \\ 1 & 0 & \cdots & n-2 & n-1 \\ \vdots & \vdots & \ddots & \vdots & \vdots \\ n-1 & n-2 & \cdots & 0 & 1 \\ n& n-2 & \cdots & 1 & 0% \end{bmatrix}% \end{equation*}. How can you prove that det(A)=[(-1)^n][n][2^(n-1)]? Thanks.

Homework Statement A 50cm long vertical current element located on a conducting ground plane radiates a 10MHz signal. 5km away from the element on the ground plane the amplitude of the signal is 0.1millivolts per meter. When the frequency is switched from 10MHz to 5MHz with current amplitude...

What is the maximum order of an element modulo n, where n is a product of two odd, distinct primes? Let t be the smallest positive integer such that xt = 1 mod n I've have been searching around on the web, but I don't really understand this concept. Some of the keyword I have found to be...

why does peak of fire of a matchstick face upwards ie away from ground.why is it not effected by gravity,is there any reason other than pressure considerations.

Dear all, I have written a code for dynamic analysis of a mechanical structure. My primary purpose is to find natural frequencies of the structure. When I test my code for a cantilever bar whose natural frequencies are known analytically, I found a big difference between the the first...

Hi, i do a motorsport where a normal cooling system for the engine cannot be used as it gets damage so we use solid water tanks along the bulkhead of the car, these arent the greatest as they tend to get hot as they're not really a cooling system at all. My idea would be to make a water tank...

Wigner-Eckart theorem and "reduced matrix element" Hello, I am studying the Wigner-Eckart theorem and I have found some difficulties understanding the reduced matrix element of a spherical tensor. In fact, a spherical tensor is commonly defined through its transformation properties, and I...

Dear all, I have written a code for structural analysis using the finite element method. For some reason, I directly started with 3D elements ( hexahedron). I used to believe that the code was fine but recently i realized that the results ( deformation, natural frequency,..) strongly depend...

I've been reading a Kabbalah book written by Yehuda Berg. "The power of Kabbalah" And it's basically explaining the universe and everything about it from the text of the zohar. And the Kaballah explains in the first few pages that Humans main core element Is Desire and in the book it quotes "If...

Hi all, A fixed-free bar has a single natural frequency. When we discretize such a bar in the finite element method, then the natural frequencies are the eigenvalues and an nχn matrix where n is the number of the degree of freedom which is usually large. Thus we obtain up to n natural...

Homework Statement The rotation matrix below describes a beam element which is rotated around three axes x,y and z. Derive the rotation matrix. http://img194.imageshack.us/img194/3351/60039512.png http://img808.imageshack.us/img808/159/64794596.png Homework Equations -The Attempt at a...

So, as the title describes, I am trying to build an infrared heating element for my own heating panel. I want to use this heater to cure an epoxy at 350F that is about 5" away. I'm an EE so the wiring and such will be simple but the heating calculations are beyond my area of expertise. Here is...

Hi all, I need to do a dynamic structural analysis using finite element method and I have a question about the mass matrix. Question: I have the force per nodes and I need to calculate the displacement of each node at a given time. For this purpose, it seems that I need to distribute the...

Hello, If we know the value of the field variables at the nodes of hexahedral element. How one finds the value at the center of the element. The hexahedral element is trilinear and solved using 2x2x2 gauss quadrature rule.

Folks, I have a query regarding the attached circuit. In order to design a rectifier, I was trying different structures. So, I started with the attached circuit without delay elements. I have used a cap at the NMOS, so that the cap will gets charged. But I don't want the cap to discharge...

So I just started learning to use the finite element package abaqus for modelling beam tip deflection under different loading conditions. I think I understand the theory behind it but was wondering if some one could answer a few questions about it to further my understanding. Firstly, how do...

Homework Statement Let R be a ring in which 1_R = 0_R .Show that R has only one element.Homework Equations The Attempt at a Solution I'm trying to show that a*0_r=a*1_r implies a*0_r=0_r. if 0=0+0=>a*0=a*(0+0)=a*0+a*0=a*1_r+a*1_r=2a=>a*0=2a= >a=0...is this correct? If not Is there something I...

Homework Statement I'm trying to write a proof ot demonstrate that every finite domain contains an identity element.Homework Equations The Attempt at a Solution If I can think of the operation from the ring as a mapping...like x->yx..where y are just values from the domain and then to consider...

How can I prove that every finite domain has an identity element? How should I think about the problem and what should I take into consideration?

I need to make a 1 metre long heating element from NiChrome Wire. The wire I have is 0.9mm with resistance of 1.7ohms per metre. Can I wire it straight to the mains with a light dimmer switch in place to limit the power?

I recently saw the Evaluated Nuclear Data File provided by Brookhaven national lab., where in i saw the plot of "Neutron Energy Vs cross section (total)" for different elements. http://www.nndc.bnl.gov/sigma/index.jsp?as=1&lib=endfb7.0&nsub=10 Now what i am interested in is, can we derive or...

Hello, I have been following this forum for some time now, but this is the first time I participate. I would appreciate if you could give me a hand in understanding the results of a finite element analysis of an automotive component we have designed. The analysis results indicate that the...

I'm studying a particular system but to ease the understanding let me take a general approach. 1) Suppose I have a system comprised of N=10^10 elements. Assuming now that I deal a damage to a random element for every timestep, I want to figure out how the damages are distributed in the...

I'm working through my rheology notes and there is a fairly basic part that I don't understand at all. If you have two neighbouring points in a liquid P(x,y,z) and $$Q(x + \Delta{x}, y + \Delta{y}, z + \Delta{z})$$ now if the velocity components of P are given as (u, v, w) then $$u_Q = u_P +...

Homework Statement Which of following statements are TRUE or FALSE. Why? In any group G with identity element e a) for any x in G, if x2 = e then x = e. b) for any x in G, if x2 = x then x = e. c) for any x in G there exists y in G such that x = y2. d) for any x, y in G there exists z...

Hi Everyone, I am working on a state space model for an electromechanical system. Part of the issue is the internal state vector ends up having interdependencies. Take the following state vector as an example: \begin{equation} X = \begin{bmatrix} x_1\\ x_2\\ x_3\\ x_4\\ x_5 \\ x_6...

I'm writing a script to simulate the transport of ion beam in a Thomson Spectrometer. My concern is that the program doesn't allow the passage of higher charge states through out the pinholes that I use to collimate the beam. I mean if I want to simulate a 3 charge states beam of C ions I will...

Please teach me this: In chapter 18.4 Peskin&Schoeder(QFT) they consider the annihilation of electron and positron to hadron.Ignoring the mass of the electron,we have: σ(e^{+}e^{-})=(1/2s)ImM(e^{+}e^{-}→e^{+}e^{-}). We have...

Ok what is your favorite element? My list includes einsteinium, seaborgium, lawrencium, fermium, and uranium. First four because they bear the name of my favorite scientists. Uranium because it is so versatile.

Homework Statement Let H be a subgroup of group G. Then H \unlhd G \Leftrightarrow xHx^{-1}=H \forall x\in G \Leftrightarrow xH=Hx \forall x\in G \Leftrightarrow xHx^{-1}=Hxx^{-1} \forall x\in G \Leftrightarrow xHx^{-1}=HxHx^{-1}=H \forall x\in G...

Homework Statement Let F|K be a field extension. If v e F is algebraic over K(u) for some u e F and v is transcendental over K, then u is algebraic over K(v).Homework Equations v transcendental over K implies K(v) iso to K(x). Know also that there exists f e K(u)[x] with f(v) = 0.The Attempt at...