Working stress design or Limit state design?« Back to Questions List
Which method is better; working stress design or Limit state design and why?

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Limit state design is better as it gives you economical section for structural members. 
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Working stress considers material strength only upto elastic limit whereas limit state considers the material strength upto ultimate value. so it gives economical results 
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deflection control requires working stress method better than limit state 
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General theory of WSD method is reducing the capacity of material. For example, in WSD method compressive capacity of concrete is considered as f’c=0.6*fc, but in USD method we consider the full capacity but a safety factor is always used in the equation.for example, f’u= fi * fc 
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General theory of WSD method is reduce the capacity of material. For example, in WSD method compressive capacity of conrete is considered as f’c=0.6*fc, but in USD method we cinsider the full capacity but a safety factor is always used in the equation.for example, f’u= fi * fc 