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perfectchaos180
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like if I was to say "this beam can take this much load" does that mean if you put any more load on it, it will crack? Sorry if this is a confusing question, help my understanding if you can.
perfectchaos180 said:like if I was to say "this beam can take this much load" does that mean if you put any more load on it, it will crack? Sorry if this is a confusing question, help my understanding if you can.
As stewartcs mentioned there is usually a limit on the principal stress in the beam. The yield stress is the stress at which permanent (plastic) deformation begins and a beam will be permanently deform. The criterion may depend on the application and margin to permanent deformation. I've seen criteria as low as 2/3 of yield strength.perfectchaos180 said:like if I was to say "this beam can take this much load" does that mean if you put any more load on it, it will crack? Sorry if this is a confusing question, help my understanding if you can.
perfectchaos180 said:like if I was to say "this beam can take this much load" does that mean if you put any more load on it, it will crack? Sorry if this is a confusing question, help my understanding if you can.
That's a good question. Obviously we can calculate the expected load carrying abilities of structures. Safety factors do play a part in allowing us to take care of all of those "unknowns" that creep up on you. However, when it comes down to it, you have to have something in place to ensure you have what you think you have. You can't do a destructive test on a beam that you want to use in your structure. That is where organizational specifications come into play. For example, in the US, most structural steel is governed by ASTM specifications. That spec will outline material constituents as well as most required parameters that have to be met for performance, i.e. minimum tensile strength, etc...||spoon|| said:I was wondering something along the same lines as the OP.
Say you have a steel beam which is a major support for any kind of structure, how do you know how much the beam can hold? Wouldn't direct testing on the beam itself lead to a weakening of the beam? And if you tested another beam of the same material and applied the results of this testing on the beam you intend to use, what is to say that the beam you choose to use doesn't have a crack or something which would weaken it? Is this where safety factors come into play?
Thanks
The amount of load that can cause a beam to crack depends on various factors such as the type of material, the dimensions of the beam, and the type of load (e.g. static or dynamic). Generally, engineers use mathematical calculations and safety factors to determine the maximum allowable load for a beam.
Some common signs that a beam is about to crack include visible deformations such as bending or sagging, unusual noises or vibrations, and cracks or fissures on the surface of the beam. If any of these signs are observed, it is important to immediately reduce the load or seek professional assistance.
It is possible for a beam to crack due to a one-time excessive load, especially if it is significantly higher than the beam's maximum allowable load. However, the likelihood of cracking also depends on the structural integrity and strength of the beam.
Different materials have different properties and strengths, which can affect their susceptibility to cracking under excessive load. For example, brittle materials such as concrete are more likely to crack under high loads compared to ductile materials like steel, which have greater flexibility and can withstand more deformation before cracking.
Regular maintenance, including visual inspections and structural analysis, can help identify potential issues with a beam before they lead to cracking under excessive load. However, it is important to also follow load guidelines and use appropriate safety factors to prevent overloading in the first place.