what is the best kind of moment connection in steel structure?
112214
If you simulate a geometrical structure in the form of an arch you will have the most evenly distributed stress.and the moment will be the same at all points.\nIf your question refers to how you tied a stell structure together ,the modern method is glue it to gether with a special glue designed for that purpose.
1002779
I think you mean the first time steel structures collasped due to fire?\n\nNo it was not the first time, it's certainly not the last time.  It happens more than people realize.\n\nI realize the following example is after 9/11:  In Paraguay on August 1st, 2004 a fire burned out of ductwork that had not been properly cleaned and ignited a fire above the ceiling in a two story shopping center with a parking deck. The fire burned above the ceiling, unoticed and eventually MELTED the steel supports and the building's roof collasped. 417 Perished.\n\nThe WTC towers what just the first time it happened on that large a scale and that publicly. The WTC fire is constantly compared to other high rise fires such as the One Meridian Plaza Fire in Philadelphia or the First Interstate Bank fire in L.A. But there is one missing component that often is not talked about. The sprinkler systems in these other fires stayed functional and kept the steel frame cool enough to withstand the fire.\n\nFire weakens and melts steel, that's why we treat the steel with protective coatings and install water sprinkler systems. In the case of the WTC, these systems were compromised or unable to protect the steel.\n\nI ran with fire and rescue in a SMALL community for about 4 years and personally saw two fires in smaller facilities (steel frame) that were not large enough to merit fire sprinklers. The roof and steel trusses gave way in both of those fires. \n\nFirefighters die every year from truss related failures, both wood AND steel, I'll admit more from wood. Check out this quote from the link below...\n"More than 60% of the roof systems in the United States are built using a truss system. By design, wooden truss systems contain a significant fuel load and are often hidden from sight. Fires in truss systems can burn for long periods before detection and can spread quickly across or through the trusses. Steel trusses are also prone to failure under fire conditions and may fail in less time than a wooden truss under the same conditions."
1030823
Shipbuilding  for example> Fabrication and assembly\nSince 1930, rivetting has been progressively supplanted by welding. This has proved more than a mere alteration in the method of connecting structural components because welding facilitates prefabrication of large component parts of the main hull structure. \n  \nBefore welding came into wide-scale use every ship was constructed on the building berth. The keel was laid, floors laid in place, frames or ribs erected, beams hung from the frames, and this skeleton, framed structure was held together by long pieces of wood called ribbands. Plating was then added and all the parts of the structure were rivetted together. In other words, the ship was built from the keel upward. \n\nThe modern method is to construct large parts of the hull, for example, the complete bow and stern. Each of these parts is built up from subassemblies or component parts, which are then welded together to form the complete bow or stern. These sections of the ship are manufactured under cover in large sheds, generally at some distance from the building berth, before being transported to the berth and there fitted into place and welded to the adjacent section. The advantages of this procedure are that work can proceed under cover, unhampered by bad weather, and the units or component parts can be built up in sequences to suit the welding operations—not always possible at the building berth itself. \n\nA number of techniques can be used to weld together two pieces of the same metallic material. The ideal weld is a continuity of homogeneous material, with the same composition and the same physical properties as the parts being joined. In steel shipbuilding, metal arc welding is produced by an electric arc formed between the parts to be joined; the fusion material is supplied by a coated electrode. The welding electrode consists of a core rod that is deposited as weld metal; it is flux coated to protect the molten metal from the atmosphere during deposition and to supply certain metallurgical properties to the weld. A great deal of research has gone into the production of the best possible coated electrodes for specific duties. The main advantages of welding over rivetting are: (1) a lighter structure (because overlaps are eliminated), (2) improved watertightness and oiltightness, (3) smoother surfaces, and (4) reduced hull upkeep. Certain precautions, however, are necessary. The design of the structure must be adapted for welding because structural details which can be rivetted are seldom suitable for welding. The joints must be carefully prepared beforehand for welding. Incomplete penetration, lack of fusion, porosity, and cracking are typical weld defects that must be avoided. Hard spots must be avoided and gradual tapering off of stiffness is necessary if defects in service are to be minimized.
656278
tepends on the type of tension...
472579
Depends on the structural design.  Shear will take place near to supports.  Load pressures will take place all the way down to the foundations (getting larger all the way.\n\nSome structures will tend to push out (like a pitched roof) and some will push down (like a flat roof). \n\nIf you need anything more specific drop me a note.
896679
A mature tree trunk may support a greater force than a fine steel wire but intuitively we feel that steel is stronger than wood. To predict the forces which a structure of any size, made of any material, can sustain without failing, we need the concept of mechanical stress.\n\nThe definition of stress originates in two observations of the behaviour of a one-dimensional body subject to uniaxial loading, for example, a steel wire under uniaxial tension:\n\n   1. When the wire is pulled, it stretches. Up to a certain load, the stretch ratio (current length / initial length) is proportional to the load divided by the cross-sectional area of the wire. We therefore define the stress as σ = F/A.\n   2. Failure occurs when the load exceeds a critical value for the material, the tensile strength multiplied by the cross-sectional area of the wire, Fc = σt A.\n\nThese observations suggest that the quantity that affects the deformation and failure of materials is stress.\n\nIn the more general setting of continuum mechanics, stress is a measure of the internal distribution of force per unit area that balances and reacts to the external loads or boundary conditions applied to a body. Stress is an example of a type of quantity called a second-order tensor. In three dimensions, a second-order tensor can be represented by a 3×3 square matrix (containing nine components). However, in the absence of body moments, the stress tensor is symmetric and can be fully specified by six components. These six components are sometimes written in Voigt notation as a 6×1 column matrix which is often, misleadingly, called the stress vector.
811039
I will try. \nNot because it is difficult to understand but difficult to describe. Let us take a three member truss.\n\nA truss must be in equilibrium otherwise it will fall into its three component pieces. Lets assume it is for a roof\n\nFrom its apex to the two walls its load will come from the tiles, and for these the angles and weights are calculated to establish what portion of it goes to which joint.\nThe two portions at the top are examined together to make sure their loads will be stable against each other.\nThe portions at the bottom are being supported by two walls but they have two components each. One wants to rest on the wall while the other is trying to move away from the wall.\nTo keep this from happening we have to introduce our third truss member and make sure it can take the tension required of it.\nNow we know all the points we can show the summation of all the loads and ascertain if they are in compression or tension.\nWhen we have selected or designed each of our truss members we can fix them to keep the whole assembly stable.\nNow the truss it in equilibrium.\nTry it with large match sticks and think of what you are reading.\nIt might help.
1097253
i'm not an engineer but i would say that there are more than one methods. i think you have to make each carrier autonomic,which means it can react as an indepenent part of the bridge in forces like wind or earthquake. i don't know if i helped, i hope i'm not beyond the subject of your question? if i'm sorry
668329
To compare the relative strengths of metal fasteners, you must compare the metals and alloys and heat treatments and thread configurations including effective diameters.  Then you must analyze the mode of failure including the entire joint design.  You must then support your statement that a structural screw is weaker than a structural bolt with pertinent specific facts before generalizing.  Good luck.
61041
I not sure if it is the same in the mining industry, but in the construction field a supplier of the similar type connectors is 'Simpson'.  They supply truss plates for different conditions. they are connectors made of steel for tie down of truss to walls etc. Friction bolts are used in areas of expansion or movement, that allows the pieces to move independently of each other, yet still stay connected. Take a look at Simpson, I'm sure they have a web site, and they usually give nice graphic images of the connectors and how they are used.
399593
Look into a product called Alumaloy. It's like welding that you can do with an ordinary propane torch. They claim its stronger than steel and will bond to any kind of metal.
901912
the moment is found by force times distance\n\nI_____v______\nI-------------------V\n\nlets say that the diagram above is the beam, the little v in the center represents the mass of the rod and the big V and the end represents the extra mass.\n\nthe moment required to resist the other forces is given by the mass of the rod times the distance from the wall (half the length of the rod) times gravity plus the extra mass on the end times the distance from the wall (full length of the rod) times gravity:\n\n(1.5 kg) * (9.81 m/s^2) * (.4 m) + (.5 kg) * (9.81 m/s^2) * (.8 m)\n= 5.886 + 3.924 Newton meters\n= 9.81 N m
855192
Steel reinforced concrete
1055782
They have the right connections
1171597
It sounds like a Civil Engineering problem, maybe for steel structures? Well, regardless, I suggest going to the ASCE (Am. Society of Civil Engineers) web site. They should have some good examples including some mesh - free finite element method solutions. Should give strengths, buckling info, etc.
530965
Pounds per square inch. Tensile Strength is expressed as the maximum load that a given material can withstand before failing. So the tensile strength of a high grade of steel might be 100,000 psi. but some steels are much lower. So if you are wanting to know what the maximum load is that you can place on the high grade of steel before it breaks, you will have to calculate what the smallest cross sectional area is that the load is being applied to. So if you have a rod that is .500" diameter the cross sectional area is 3.1416 X (Radius.250 squared)=.19635 square inches. So if 1 sq. in. will hold 100,000 Lbs. then you can multiply .19635 sq. in. by 100,000 psi to find pounds that .500" diameter rod will hold which is 19,635 Lbs. A .500" diameter bolt from the same material will hold less due to the reduced cross sectional area at the minor diameter of the threads on the bolt.  The diameter of a bolt always refers to it's nominal Major Diameter. The Minor Diameter has to be calculated, measured, or found in a table. In engineering practice a safety factor (increased cross sectional area) is added which may range from 200% to 1000% or more depending on the application. Material fatigue, vibratory loading, dynamic loading, corrosion, etc. and the possible dangers to people and property from under-engineering must always be taken into consideration in addition to this simple calculation for safety's sake.
249682
Looks like you are reading the book only. sometimes you have to get into some experiments, lab work to get better understanding.\n\nMechanics is the most Important part of physics or any dynamic structural analysis. To get better unserstanding ask your teacher to give you real time examples to solve.\n\nIf you do not understand the basics of Mechanics of materials, you'll have hard time to understand the properties and the analysis part in the future.