Top chord out-of-plane stability is key for design this type of structure. Here is one example I prepared before. Different load capacities could be derived with different unsupported compression lengths (out-of-plane) specified in FEA.
The structure is not same, but design principle is. In...
Top chord out-of-plane buckling could be the reason. vatical hanger and bottom chord do not provide enough lateral support stiffness to the top chord. What the unsupported length of the top chord is in you FEA simulation?
Here is a post on LinkedIn which may help understand why the collapse...
Those modes with small mass participation factors are local vibrations. The local vibrations do not affect dynamic analysis and design f the structure as a whole. You can not model those members in your FEA to facilitate dynamic analysis.
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Shu Jiang, SE (Nevada)...
W beams were simulated with 1D element, X bracing between the beams can not be simulated in the fea model. You could specify beam lateral support distance equal to X brace spacing. And hand check brace angle strength and stiffness requirement per Aisc appendix 6.
You have to simulate beam with...
Not only dead load of structure and equipment, mass shall also include some percentage of live load in some cases. You may go back to ASCE 7 for more information regarding seismic design.
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Shu Jiang, SE (Nevada). PE(Michigan, South Dakota), PEng (Ontario)
J&J Structural...
Figure 28.6-1 of ASCE7-10 show the wind load on wall and roof of low-rise building,
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Shu Jiang, SE (Nevada). PE(Michigan, South Dakota), PEng (Ontario)
J&J Structural Consulting Inc.
Structural design, analysis, inspection, drawing review and stamping, and connection design
Ultimate shear stress is Fu/sqrt(3)=0.6Fu and shear yield stress is Fy/sqrt(3)=0.6Fy. The formula k1-3 is to guarantee the configuration of the connection geometry to ensure that the chord shear yield stress is larger than the plate ultimate shear stress.
You can calculate the maximum allowable...
Shear wall theoretically can resist shear in the plane of the wall only. You have treat the “C” shape wall as two section: the “web” take horizontal force in plane along the “web”; the “flanges” take the horizontal force perpendicular to the web only.
Extra torsion due to the eccentricity of...
Check punch strength, conservatively treat the slab as one way slab and check bending and shear strength respectively. There would no worries if all the three items are acceptable.
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Shu Jiang, SE (Nevada). PE(Michigan, South Dakota), PEng (Ontario)
J&J Structural Consulting...
The supporting structure normally be designed to take the marked trolley lifting load plus all related equipment/structure self weight. Appropriate load factors for each load is considered too.
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J&J Structural Consulting Inc.
Structural design, analysis, inspection, drawing...
For your information.
An 80 feet dimeter concrete tube with 4” thick wall. Investigate the maximum external buckling pressure of the tube can take. The maximum buckling pressure shall be q=3EI/R^3 (strength of materials: part II Advanced theory and problems – by S. Timoshenko).
Assume the...
You do not need to consider rotary inertia whenever the support is coincident with the (equipment (mass) rotation center.
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J&J Structural Consulting Inc.
Structural design, analysis, inspection, drawing review and stamping, and connection design
The shell seems extreme thin per the dimension of the arc. Is this the right dimension?
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J&J Structural Consulting Inc.
Structural design, analysis, inspection, drawing review and stamping, and connection design
“Plain bars are permitted only for spiral reinforcement used as transverse reinforcement for columns, transverse reinforcement for shear and torsion, or confining reinforcement for splices.”
Yield strength less than 100ksi is normally acceptable. The tie diameter shall be determined by the...
Use section 29.5 of ASCE 7 2010 calculate wind load. Apply the load to any member not being shielded in the leeward wind directions.
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J&J Structural Consulting Inc.
Structural design, analysis, inspection, drawing review and stamping, and connection design
