Failure Definition and 248 Threads

Homework Statement (a) Suppose we flip a fair coin until two Tails in a row come up. What is the expected number, NTT, of flips we perform? Hint: Let D be the tree diagram for this process. Explain why D = H · D + T · (H · D + T). Use the Law of Total Expectation (b) Suppose we flip a fair...

I want do thermal and structural analysis (Failure) on gas turbine blade. So what how to begin. Kindly help me.

Hi, so when doing a tensile test let's say on a threaded bar and a nut. The nut thread reaches failure and shoots off. How would you calculate that velocity and the actual force that it would hit say a wall 20cm away. just for information the failure point was at about 300kN

Question: A 7750 kg rocket blasts off vertically from the launch pad with a constant upward acceleration of 2.35 m/s^2 and feels no appreciable air resistance. When it has reached a height of 555 m , its engines suddenly fail so that the only force acting on it is now gravity. Part B: How much...

Am experimenting with an Omega Engineering AHP 7561 standard air heater rated for up to 240v. Specs include ability to keep a 20 cfm flow exiting @1000F while pulling about 10A @220v. Nichrome melts around 2400F. I'd like to produce small bursts (lasting a few seconds) of very hot air, like...

The following comes from Griffiths Intro. to QM (2nd Ed) page 53. We want to solve the Schrödinger Equation for the harmonic oscillator case using a power series method. The details aren't important but you want to solve ##h''(y)-2yh'(y)+(K-1)h=0## whose recursion formula is...

Is there any method to define weather I have to calculate for determine buckling of column lead to fail or not. Is there is any rule of thumb or formula that show it is required to check for buckling or not (like very short column)

I'm trying to double major but I fell behind taking pre med bio classes so I may need to overload this next semester Freshman/sophmore level physics classes 1. This course covers the topics of: electromagnetic waves, optics, and modern physics, condensed matter and nuclear physics. 2. The...

Homework Statement Hi guys (first post here let me know if I can fix anything that I've done wrong), I'm struggling a little with the second part of this question and seem to be going round in circles A column has the dimensions shown in the diagram below. (a) What is the minimum length of...

I purchased this car new 2013, 29,999 miles and the dealer has been the only one who worked on it. We use synthic oil. After driving the last 100 mile at 60 mph the engine stopped. I had it towed to the dealership. The lower end of #4 con rod was sticking out of the Aluminum block. The...

Homework Statement Suppose components A, B1 and B2 operate independently, in a system below, and the probabilities that anyone of the components will operate for 100 hours without failure are P(A) = 0.8,P(B1) = P(B2) = 0.9. The system works if A works and either B1 or B2 works. Find the...

Homework Statement Not homework but this seems the best place to post this. In a private conversation someone posted this explanation from a book on how a lamp filament fails.. I'm having some trouble doing the maths to show that the thinner higher resistance part gets hotter... Homework...

Hi all, I have a problem which is quite basic, and I must be missing something. Fe 3+ + e > Fe 2+ +0.77v O2 + 4H+ + 4e > 2H2O +1.23v Re arranged, this tells us that if we bubble air through iron 2 sulphate solution, acidified with H2SO4, the oxygen should oxidise the Fe 2+ to Fe 3+...

I am a part C Mechanical Engineering student and have been undertaking a project investigating the strain sensitivity of a particular glass filled composite. From my quasi-static results, the stress-strain curves seem to be reasonable and match that of the mechanical material properties...

Hey, all, So I posted a similar thread yesterday about my project design issue, but I've made progress on it by taking a different approach. For the project, I have a cantilever shaft of fixed length (1.2m) and a tensile axial loading, and two torsional loadings in the same direction at...

I'm in a sophomore-level general engineering class (mechanics of materials), and I was assigned a project that I had a good idea on how to tackle, but I'm running into an error. The project: I'm given a 1.2m long cylindrical cantilever with forces acting on it; one axial tensile force, and two...

I'm a second year physics student and since last year I've been noticing that an old habitis becoming a serious problem: when I can't solve some exercise in a set, I literally can't do anything with respect that subject until I solve it. It has became something quite similar to an OCD. I already...

Hello. My professor has asked the class to find a few reports of failure analysis. We need reports that contains high quality pictures of the failed component and the data of the failed component. Also we can not have a failure report with amorphous materials(glass, plastics ect) Links or...

Hi all, I'm three months into my PhD after taking a 2 year break between it and my BSc to work in government. I went back to academia because I thought I wanted to be a scientist - a proper researcher! However, I'm finding that my enjoyment and motivation to do the work has fallen to zero. I...

People with congestive heart failure (CHF) are advised by doctors to restrict fluid intake. For example, while 8 cups of fluid per day is recommended for healthy individuals, people with CHF are recommended not to exceed 4 cups a day. The explanation, according to a medical student friend, is so...

I could not qualify for JEE Advanced. I completely lost my dream of studying physics at IIT. I am going to take admission in computer science at a crap college. My 12th marks are very low to study physics at local colleges too. So i had no other options but to opt for computer science. I always...

Homework Statement A circuit board has 20 integrated circuits(ic) with constant failure rate of 5 chips per million per hour (5FITs), 300 resistors(r) with a constant failure rate of 20 chips per million per 1000 hour (20 FIT), and 10 diodes(d) with a constant failure rate of 10 chips per...

guidance on math "failure" Can someone please give me some feedback on why I am having such a hard time with abstract math? I went went from almost straight a's to barely being able to solve a problem in number theory. I had someone tell me that it is like I have storage spots in my brain...

I have been photographing wires hanging from utility poles that have tangled with and caused automobile accidents. One of these is a puzzle the detail shows a wire from a 7 strand wire rope made out of aluminum. It was too dangerous at the time to anything but drag the wire out of the road and...

Hi All, So here's the problem. A project I am working on has a composite metal panel assembly, which a previous engineer designed. The metal panels are simply glued to the polystyrene (styrofoam sm). The problem is that the previous engineer did not consider the difference in thermal...

Hi, My name is Hari and i am new to this forum. I am currently working on a research problem using Newton rhapson method to find solution for a system of non-linear functions. The precise application is Inverse Kinematics of manipulators. However, i have three non linear equations function of...

Hello. I'm trying to make a "Mach–Zehnder interferometer", that would show a same-named paradox. In plain words: Two half-silvered mirrors, two full mirrors, the beam is split, then merged together. At the merge point one way the photon is canceled out, while the other way it is combined...

Homework Statement I am doing my internship at Saint Gobain Glass India, Chennai . I have been allotted a project to work in my time at the company . The problem is related to failure of an Mild Steel beam supporting graphite structure in the process line . As such this beam is exposed to...

So i am confused on how to do the analysis on the pin where the hook attaches to the arm. would their be a shear and a torque at that point?

Has this occurred to you folks during your undergrad days? How did you overcome it? It seems at this point, my fear of failure is stronger than my passion and my abilities combined which is a very dangerous mindset to have. As they say, misery loves company and I was just wondering if...

Homework Statement Hi all, I have a question about a standard flat key being specified to prevent failure. I'm just quickly giving a problem description because once I understand what's going on I can easily run calculations but I'm missing something fundamental. Essentially the problem I...

hi there, I'm currently facing a problem with the silicon rectifier, http://www.alldatasheet.com/datasheet-pdf/pdf/35499/RECTRON/6A8.html with the current setup which is at the attachment. The source is a AC current of 230V 50Hz , while the cap is at 0.3μF. The setup is to provide...

Homework Statement In a sequence of independent trials with probability of success p, what is the probability that there are r successes before the k-th failure?Homework Equations Binomial distribution f(x;n,p) = {{n}\choose{r}} p^{x} (1-p)^{n-r} The Attempt at a Solution I know that the...

When does the Classical Heat transfer fail / stop to work , i.e, when will the quantum effects have any effect on the heat transfer. My problem is a heat transfer between a Spherical Bacterial Spores(an agglomerate) and a hot gas (take Nitrogen) . I really don't know whether the spores can be...

Hi everyone here! I'm a LSA and PPL pilot, working on my CPL, and I have some questions to those who have knowledge of the aeroelastic effects and flutter phenomenon. I would like to talk a little about aerodynamic flutter onset speed and flight control malfunction. It is known that freeplay...

Problem deriving "failure of simultaneity at a distance" Homework Statement I'm trying to derive the failure of simultaneity at a distance from the spatial part of the Lorentz transformation. In his treatment of the subject, Feynman glosses over the algebra/derivation and produces the...

This was the sub-forum where I thought I may be able to find any help in, so I really hope I didn't go wrong there. So, dear readers, I come to you because I have ran out of options to get me out of the mess I find myself to be in right now. If you could lend me your honest thoughts and advice...

If at very large scales of matter our intuitive logic fails to explain it (Black Holes) and at very small scales of matter untuition again fails (Quantum effects) then is there a connection between those two groups of phenomena?

I have a 13 layer 130mH induction coil that failed and now registers 6.64mH. During the failure analysis the coil was unwound layer by layer and the induction dropped in steps of 0.7-1.5mH to a value of 1.3mH until the 8th layer was removed the the inductance increased to 5.4mH. Then the 9th...

Hi, I have been using a tensiometer to help me try and determine what the material is. one of the materials has been heat treated and and instead of a nice necking formation in the middle of the "dumbell sample" it has fractured perpendicular to the sample right next to the chucks of the...

Hello, First post, go easy. Trying to do some basic calculations on how to find when a steel cantilever beam will yield when a load is applied to the free end of the beam. I have attached my best MS Paint diagram of the problem. Assume the left end is clamped and essentially a fixed end...

I am currently working on a project to determine how much weight a mild steel shelving units can support. This is a project for a friend and for my own interest. I am having trouble deciding exactly what is necessary to determine the weight the shelving units will hold. Each shelf on the unit...

Hey guys, I'm an 18 year old living in Australia. Throughout my primary and high-school career I've always been either a below average or a mediocre student, I finished my high-school certificate receiving very low marks in my final year of schooling, which has since left me with feelings of...

I'm not that familiar with the inner workings of solid state relays, and I'm seeing an unusual anomaly in my circuit that I'm not quite sure how to explain. For my job, I'm running tests on some sensors. One of the requirements for the test is to turn the power to the parts on and off...

I will show you my (obviously wrong) way of thinking when i have to apply an integral. Please correct me where I'm wrong. (imaginary question) Suppose you have a mass distribution across a line, where the mass of each point is given by the equation f(x)=a*x (assume a is a constant) find...

Rotating Coupling Pin--Mechanical Failure as a Safety Precaution Hi everyone, I am RagingCalm, a mechanical design engineer. I hate to ask for help on my very first post but considering that I am utterly stumped and no one at the office can help me...well...ummm...help, please. :frown...

This is very weird, but I found an inconsistency in the application of Cramer's Rule for a 3x3 simple linear matrix. 1x + 1y + 0z = 3 -1x + 3y + 4z = -3 0x + 4y + 3z = 2 Dz = 1 1 3 -1 3 -3 0 4 2 If you take the determinant across the first row To find Dz, I constantly get...

Something happened last night and one or more things failed in the home network. For years it has been three computers running XP with fixed IP addressess hard wired to an SMC 7400VBR router hard wired to a Motorola SB5120 Surfboard cable modem. Nothing wireless. Cyberpower UPS and power...

[First post here, please make allowances..] I want to use a triac as a solid-state SPST switch for a normal 120VAC receptacle. The on/off state will be controlled by a low-voltage DC circuit through an opto-isolation MOC3020. http://ken.coar.org/images/opto-triac.png So far so good...

Hello, I hope this is the right section to post this in. I just finished my first year at university studying computer science and engineering and only managed to pass on roughly half of the courses I took. I have googled a bit and read around here on this forum to get bits and tips on how...