What is Load: Definition and 1000 Discussions

A structural load or structural action is a force, deformation, or acceleration applied to structural elements. A load causes stress, deformation, and displacement in a structure. Structural analysis, a discipline in engineering, analyzes the effects loads on structures and structural elements. Excess load may cause structural failure, so this should be considered and controlled during the design of a structure. Particular mechanical structures—such as aircraft, satellites, rockets, space stations, ships, and submarines—are subject to their own particular structural loads and actions. Engineers often evaluate structural loads based upon published regulations, contracts, or specifications. Accepted technical standards are used for acceptance testing and inspection.

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  1. W

    Load, Deflection, rotation, Designing basic beam?

    Homework Statement The problem is in attached. Desgining basic beam Homework Equations M = E*I(d^2*w/dx^2) slope = E*I (dw/dy) = integral of E*I(d^2*w/dx) + c1 deflection = E*I * (w) = double integral of E*I(d^2*w/dx) + c1x + c2 ΣM*= 0 ΣFx = 0 ΣFy = 0 Yb = ΣAY / ΣA I =...
  2. L

    Math Student: Semester Load Advice

    I am a math student at Queens College and so far I have taken the freshman calculus sequence up to multivariate calculus, calc based probability, discrete math, linear algebra I, and ordinary differential equations. Right now I am registered for the following classes for the Fall '11...
  3. M

    What Determines the Critical Load in a Pinned-Fixed Rod with a Torsional Spring?

    Homework Statement A rod of leangth L and flexural rigidity EI is pinned at one end by means of torsional spring having a constant beta, and fixed on the other end. The rod is subjected to a compressive axial force P. Determine the critical load for instability.(image of the problem is...
  4. R

    Bolted flange Joints load calculation

    I'm joining a flange and a cap using 9 bolts with a steel gasket placed in a 'o' ring. To ensure that the joint is leak proof, I need to calculate the load distribution in the area between two bolts for a given torque in the bolt[please refer to the figure, where the lines indicate the area...
  5. N

    Determine Reflection Coefficient & Load Impedance: Slotted Line 150ohms

    A slotted line used on a 150ohm lossless transmission line connected to an unknown load impedance, ZL. The voltage standing wave ration is found to be equal to 3. The distance of the first voltage maximum from the load is found to be 9 cm, and the first voltage minimum is located at 3 cm from...
  6. A

    Gross Weight Load: Can It Be Used for Railcar Gravity Force?

    Dear native English speaking professionals! Would someone please advise on the term "gross weight load" - is it possible to use it for gravity force of a fully loaded railcar? I use it in the following context: "Estimated vertical force on one chord section is assumed to be equal to...
  7. O

    Engineering Trying to calculate from motor output to FLA(Full load amps)

    Homework Statement Fan Motor Output: 0.172 kW Propeller Fan Compressor Motor Output: 2.9kW DC Inverter-driven Scroll Voltage: 208/230, single phase What I need to find is the FLA for each fan motor(2), and the FLA of the compressor motor. Total MCA = 32A Homework Equations...
  8. I

    How Can a Buffered Band Pass Filter Be Designed with an Infinite Resistive Load?

    Hello, I have a question. How do you design a buffered band pass filter with a resistive load of infinity? I have a feeling that a resistor with a resistance of infinity is an open circuit. Although how can this be implemented in a type of filter seen in the attachment? Thank you.
  9. N

    Question on the switching loss of inductive load in SMPS.

    Homework Statement Hi everyone, I have a question on the SMPS. I am studying the switching loss due to the switching action using a mosfet, it was clear in the resistive load part, the amount of loss is the integration of the changing voltage and current through the switch. However...
  10. B

    Unbalanced star connected load with neutral

    Homework Statement An unbalanced, star connected load with a neutral connection has resistances of value 2,4,1 in the a,b,c lines, and a resistance of 3 in the neutral. Find the current flowing in each line and in the neutral Homework Equations I think: Va = ZaIa + Zn(Ia+Ib+Ic) Vb =...
  11. H

    PFN charging a capacitive load?

    I am trying to understand how a PFN (Pulse Forming Network) could charge a capacitor to a high voltage and I have some questions first. Is there any type of voltage multiplying PFN which does not use switches or spark gaps? (The only type I have seen is the Marx type which uses either...
  12. U

    Calculating Load from Modulus of Rupture

    Homework Statement There is a structure with four legs. each leg is 6" x 6" square. The bottom of each leg is 6"W x 6"L x 3/4" H. Each leg has a foot which is 4" x 4" x 4". The foot is placed in the center of the leg. The question is how much weight can the legs support before the bottom of...
  13. S

    Load on a journal bearing in a vertical shaft

    i have to design a journal bearing for a vertical motor shaft. what loads act on these bearings? since the shaft is axial, are they any loads that act on the bearing. here i am talking about journal/plain bearing, not the thrust bearing which supports the vertical load. what type of failure we...
  14. S

    Shear force with a mirrored triangular load

    Homework Statement Determine shear force at point D of Beam http://tinypic.com/r/339m5b6/7 Homework Equations Sign conventions for cut at d when considering LHSFBD M = xFy - yFx - cross product... The Attempt at a Solution I've found the reaction forces by finding the sum of moments...
  15. A

    Understanding Delta & Star Load Connections

    why do we require delta and star load connection ? thanks.
  16. B

    Difference in current to load with series/parallel sources

    I feel this is a very simple question, but I can't seem to wrap my head around it. For example, if you have two 1.5 volt batteries in series and a load of 100 ohms then the total voltage is 3 volts and the current is 30mA because I=V/R. If you have two 1.5 volt batteries in parallel then the...
  17. A

    Effort Required to lift a load using third order lever

    Homework Statement Calculate the effort required to lift a load of 1962N using a third order lever with load 5m distance from effot and fulcrum 1m distance from effort. Homework Equations i used the following, large distance x small effort = small distance x large effort The...
  18. Femme_physics

    Statics - Truck's max load in center of mass

    Homework Statement During the weight-in of a truck it's been determined that the load of the weight acting on the front axis and back axis are 18 [kN] and 12 [kN] correspondingly, when the truck is empty as shown in the diagram. The max load allowed on every axis is 40.Calculate the size of...
  19. P

    Load Control Circuit: Reduce Wasted Power in Design

    Hi, all. (please see the attachment in the next post) I'm re-using an old power converter in a design, which unfortunately requires a rather large minimum load to properly regulate. I can't alter this converter; I have to use it as-is. But, I can monitor the output, and add circuitry as...
  20. A

    Distributed load - model bridge project

    Homework Statement check out: so this is for a bridge project right and that picture is simply a basic design just enough to get the jist to answer my question. what I am wondering is, if 20kg's was applied to the very centre of that loading plate - is it fair to say that each of the long...
  21. N

    Static equilibrium: Elastic rope with load

    Homework Statement It's not possible for me to solve this problem. Maybe work/energy relations is required ? Homework Equations I've ended up with polynomiums of 3. and 4. degree, trying to find the roots. But finding the...
  22. ddelaiarro

    Correlating Temperature to Solar Load

    BLUF: Is it possible to mimic a solar loading environment solely in a temperature chamber and, if so, how? We have an 6061 Aluminum box with a known heat load inside. It needs to be subjected to a solar load IAW MIL-STD-810G, Method 505.4, Proc I. Essentially, it is a 24-hour exposure cycle...
  23. D

    Finding the acceleration of a crane trolley and it's load.

    Homework Statement An object of weight 8526 N hangs at an angle of 5.0° when the crane’s trolley at point P moves to the right with constant acceleration, as shown in the diagram. Calculate the acceleration of the trolley and load. Homework Equations 9.8 / tan (90-5) = 0.857 m/s^2...
  24. 5

    Applying Load on an area - ANSYS APDL

    Hi, Have been using ANSYS Mechanical to conduct some analyses, but am now moving to ANSYS APDL to investigate the effectiveness of Solid-Shell elements. However, I've run into a problem. I can't figure out how to apply a load to an area! I have been playing around with the SURF154...
  25. A

    Calculating Maximum Distributed Load on Beam Using Failure Theories

    Having a hard time with failure theories. Beam length 20 feet, 6"h x 4"w. sigma yield is 40 ksi. How to calculate the maximum distributed load the beam could carry using von Mises and Tresca failure theories. I have my shear and moment diagrams drawn and know they are right. I found that...
  26. D

    Mechanics of material: an Axial Load Problem

    Hey Guys, here is a skeleton for an exercise I need a help with: In this Problem we have a beam EF which is pin-supported at E, a Rod CD which is enrolled by a spring ( spring constant =k) and a rod AB (AB is touching the ground, I forgot to draw it). If we heat the Rod AB what will...
  27. B

    Why do electrical generators experience load effects?

    I was wondering why it is when you use the electricity from an electrical generator, it bogs the generator down? Shouldn't the draw off of electricity negate any sort of back flow there by making it easier on the generator to function?
  28. C

    MATLAB How to load a non-rectangular array into MATLAB?

    We have a sensor in the lab that measures two quantities and uses two different sampling rates. All four of these vectors are saved into the same text file. How can I load this into MATLAB when it is non-rectangular? Thanks for your help.
  29. R

    Radio Astronomy Cold Load Question

    Hi, I'm reading about the discovery of the cosmic microwave background radiation and don't understand this part ... What power does a source called with liquid helium produce and how is it related to the amplifier circuits ? I don't get what they did and why ? Thanks !
  30. Z

    Estimating Car Engine Temp. with Load: A Simplified Approach

    Hello Can someone tell me basic equation of car engine temp. that depends on load. I don't need a precise equation - i need something simplified for simulation.
  31. D

    DC motor - Enough torque to rotate load?

    Hi all, I am new here as i want to ask something about an engineering project i am working on. I need a motor to rotate a 200 grams cylinder which will be hanging from the motor's shaft (vertically). I wanted less than 100 rpm so the motor I chose is a 2.1W 6V DC motor with a 50:1 reductor...
  32. C

    Max Load for Beach Mattress on Dead Sea Surface: 142.8 kg

    Homework Statement A beach mattress filled with air has a volume of 120 L and a mass of 6.0 kg. The saline water of the Dead Sea has a density of 1240 kg/m3. Assume that the mattress retains its shape and volume regardless of load. Homework Equations What is the maximum load the mattress...
  33. M

    Calculating load rating of a pulley stand

    Hi Guys, I'm a mechanical engineer looking for help with a structural problem, I work on-site at an iron ore mine in Western Australia. Typically once we design stands we get them fabricated then sent for certification. Certification involves a company putting the load which we wish to get...
  34. V

    Weird problem for finding load resistance value.

    Hello 2 all ! I am a student on electrical engineering, and i have the following problem to solve: Homework Statement An electrical circuit includes a dc voltage source with an internal resistance, and a load resistance. Determine the value of the load resistance R (with a precizion...
  35. C

    Calculating Force Needed to Pull Sled with 210kg Load

    Homework Statement Sled dog to pull on a snowy sleigh horizontal road, the mass of its load is 210 kg. Snow and sleigh runners movement between the friction coefficient is 0.095. Dogs sleigh force exerted by the horizontal. acceleration of 0.13 m/s2? Gravitational acceleration is 9.81 m/s2...
  36. W

    Finding the deflection using the unit load method.

    Homework Statement A uniform beam, supported by a uniform strut, is loaded as shown in Figure (Attached). Using the unit load method, determine the value of the vertical deflection at C. BEAM: E = 205 kN/mm2, I = 90 x 106 mm4. STRUT: E = 205 kN/mm2, A = 1500 mm2. Homework Equations...
  37. O

    What is the formula for bending stress of a plate with a central point load

    I have a steel deck (a) 2000mm x (b) 4200mm overall comprising 12.5mm durbar plate (grade S275) welded to RSA ribs at 400mm spacings, the plate is unsupported in the other plane (4200mm span) with the exception of end plates. I wish to drive a forklift truck over the plate with a wheel load of...
  38. J

    Calculating stiffness from load and defletion

    ok i loaded a composite laminate beam across the centre of a 1.44meter span with 415N load. This deflected the beam to a distance of 0.05m (5cm). Im having trouble calculating the stiffness from this. The composite laminate is 5mm of wood in a glass fiber sandwich with both the top and bottom...
  39. E

    Full Load & No Load: Meaning in Motor Context

    What is the meaning of full load and no load, in the context of motor? Does the load here mean mechanical load?
  40. K

    What is the force that slows a generator down when a load is applied?

    hi, everyone know that when electrical load is applied to a generator, the generator slows down. Now my question is what actually slows the generator, what kind of force and how much is that force this question my sound weired to many but i need a very definate answer. thanks in advance
  41. J

    Husband found this fossil in a load of gravel

    My husband found this fossil in a load of gravel that was delivered to our home here in northwest Nebraska. Can't say for sure, but gravel is probably from this area or maybe southwest South Dakota. The fossil is 5 1/2" along outside curve and 1 3/8" in diameter. You can see in the photos...
  42. F

    Minimum strength of pipe for load bearing

    Hello, I am working on a project and I came across a question that is a little beyond my skill set. I am designing a support for a roof, and I have the force into the post, the length of the post and I need to determine what pipe I need, size, schedule diamter, etc. How do I go about this...
  43. H

    Cantilever beam with horizontal and vertical component point load at free end

    How do you calculate the stress in a cantilevered beam with a point load at the free end where the load has a large horizontal component loading the beam in tension as well as bending from the vertical component? And the beam bends far enough so it's slope will match the slope of the load at...
  44. X

    Patch load on stiffened panel ?

    I need help analyzing a load scenario. I have a stiffened panel with fixed and pinned edges. There are fairly sturdy stiffeners equally spaced below the panel. There is a uniform patch load (pressure) that can be applied at any point around the panel. I need to determine the resulting stress...
  45. S

    How do I calculate the moment of load on an arm?

    Homework Statement Homework Equations So moment and torque are really the same, right? so the force times the distance. The Attempt at a Solution The force used has to be perpendicular to the line of the radius about O, so I assume I must do cos(36)*6lb*5in for the first. The...
  46. B

    Schools How much does your course load each semester affect grad school admission?

    I'm currently double majoring in ChemE and physics with the intent of going to grad school. This semester I'm taking 6 courses this semester totaling 19 hours, with about 10-15 hours per week spent in a research lab. I was considering dropping one course and taking it another semester, but I...
  47. P

    Formula for a non-uniform distributed load on a flat plate

    Homework Statement I am writing a MATLAB code to predict plate displacement for multiple load conditions using the rayleigh-ritz method. I have gotten the first three loads but I am struggling with the last load case. I need to represent a distributed load for a flat plate that is piecewise...
  48. J

    Axial load strength of PVC pipe

    Hello, I design high powered rockets in our Tripoli rocket club. A particular plastic type of tube used is the Quantum 3.9 in dia plastic (sewer pipe) it is a thin wall design. http://www.publicmissiles.com/ They state that this basic tube is good for just .86 mach for compression loads...
  49. L

    Levitating Magnet with Load of 12oz: Shielding Electronics & Transmitter

    So basically i have this powerful electromagnet that generates an electromagnetic field that can levitate another magnet and withhold a load of 12oz and still levitate: My problem is, I want to be able to use electronics and send wireless signals through this strong magnetic field. I can...
  50. W

    Max. torque on a shaft with an unbalanced load

    I'm new to the forum and hope someone can help me out. I've attached a picture so hope it works. I have a ladle for pouring metal, the mass of the ladle itself is 60kg and the max. mass of material that can fit in the ladle is 90kg. Total mass 150kg. The ladle has a tapered profile, so the...
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