In many engineering design codes, the limit state method has replaced the working stress method. The limit state method is a safety-based approach that considers both the static and dynamic loads that a structure may experience during its lifetime. The working stress method, on the other hand, only considers static loads. The limit state method is a more comprehensive approach that leads to safer designs.
The working stress method was the traditional approach to design, but the limit state method is now the preferred approach in design because it provides a more accurate representation of the strength of a structure. The limit state method is a more sophisticated approach that takes into account the variability of material properties and the effects of loading on a structure, while the working stress method assumes that materials are perfectly homogeneous and that loads are applied evenly.
Why is limit state method considered more desirable than working stress method?
The limit state method is a more advanced approach to engineering than the working stress method. It is based on predictions of how a structure will behave under certain loads, rather than assuming that the loads, material stresses, and factors of safety are known accurately. This makes the limit state method more versatile and able to deal with more complex situations.
Serviceability check in case of LSM is required because after the elastic region strain is higher, which results in more deformation, hence a check is necessary.
LSM is strain based method whereas WSM is stress based method. LSM is non-deterministic method whereas WSM is deterministic approach.
What is the difference between limit state method and working stress method
In limit states design, we consider the structure to have reached its failure point when it reaches the lower yield point. In working stress design, we calculate the design strength such that the stress in the material is restrained to its yield point, under which the material follows Hooke’s law. Hence, the term “elastic” is used.
Limit states are the acceptable limits for the safety and serviceability requirements of the structure before failure occurs. The design of structures by this method will thus ensure that they will not reach limit states and will not become unfit for the use for which they are intended. This will help to ensure the safety and longevity of the structure.
What is the basic difference between LSM and WSM?
There are two main methods used for designing structures: the Working State Method (WSM) and the Limit State Method (LSM).
The main difference between the two methods is that WSM is an elastic design method while LSM is a plastic design method. This means that the WSM takes into account the flexibility of the structure while the LSM does not.
The advantage of using the WSM is that it is more economical because it utilizes the “moment-rotation” capacity of beams. The downside is that it is more complicated and requires more calculations.
The LSM is simpler and easier to use but it is not as efficient. It is also more likely to result in a structure that is not as strong.
WSM is not an economical approach as it gives larger section of structural members. Additionally, it assumes that stress and strain relationship is constant for concrete, which is not accurate. Finally, WSM does not consider the mode of failure of the structure (brittle or ductile).
What makes LSM great?
Your LSM is a versatile player who can shut down the other team’s best midfielder, take the ball away, pick off passes, and push the ball quickly to the goal. They have the instincts of a midfielder and will run past a few guys on the clear. They love defense and want to score goals.
‘The Limit State Method (LSM) is a design approach for reinforced concrete (RC) structures that evolved during the 1950s. It gave economical design of RC structures due to the use of smaller section dimensions and full utilization of both steel and concrete, as compared to the Working Stress Method. The stress levels in materials were higher in LSM, but this was offset by the increased strength of concrete and steel developed during the 1950s. The LSM was codified in Eurocode 2, which is the design standard for concrete structures in the European Union.’
What is the assumption of LSM
When designing a structure, it is important to consider the limit state of collapse. This is the point at which the structure will no longer be able to support itself and will collapse. There are several assumptions that are made in the limit state of collapse:
-The tensile strength of concrete is ignored. This means that the concrete will not be able to resist any force trying to pull it apart.
-The maximum compressive load of the structure takes by the concrete. This means that the concrete will be the primary support for the structure and will bear the brunt of any loads applied to it.
-The steel takes the maximum tensile load of the structure and takes a little bit of compressive load. This means that the steel will be responsible for holding the structure together under tension, while also taking on some of the compressive loads.
-There should have a perfect bond between steel and concrete. This means that the connection between the two materials is crucial in ensuring the overall strength of the structure.
The above mentioned assumption is made according to IS 456 in limit states of collapse. This means that the cross section of the concrete beam will not change after bending. The maximum strain in the concrete at the outermost compression fiber should not exceed 0.0035. The tensile strength of the concrete can be ignored.
What is working stress method?
The working stress method (WSM) is a simple and commonly used approach for designing structural elements. The method basically assumes that the structural material behaves in a linear elastic manner, and that adequate safety can be ensured by suitably restricting the stresses in the material induced by the expected “working loads” on the structure.
The main advantage of this method is its simplicity. However, it has some limitations. Firstly, it is only applicable to materials that behave in a linear elastic manner. Secondly, it does not account for the effects of fatigue and creep, which can lead to failure of the structure over time even if the maximum stresses are within the allowable limits.
Despite its limitations, the WSM is still a widely used approach in structural design, especially for simple structures where the loads are well understood and the material behavior is relatively well-behaved.
The main difference between LSD and LRFD is that LSD is a prescriptive method, meaning that it outlines specific rules and regulations that must be followed, while LRFD is a performance-based method, meaning that it assesses the ability of a structure to perform its required function.
LSD has been the traditional approach to structural design, and is still used in many countries. LRFD is increasingly being used in North America and other countries, as it is thought to provide a more rational approach to design.
Why is serviceability limit state considered as important as failure limit states
A serviceability limit state is a condition where a civil engineering structure does not meet technical requirements for use, even though it may be strong enough to remain standing. A structure that fails serviceability has exceeded a defined limit for one of the following properties: Excessive deflection.
The reinforced concrete design Working Stress Design Method is a method used to create stronger concrete structures by assuming that concrete is elastic and that steel and concrete work together elastically. This method allows for a linear relationship between loads and stresses, which results in stronger and more durable concrete structures.
What is the difference between working stress method and limit state method quora?
The working stress method considers the actual working load for the design purpose, while in the limit state method we consider the factored load for the design purpose. The factored load means the increased value of the load, which are not actually applied on the structure.
The limit state method is a possible approach for design, but it has several disadvantages. It cannot provide sufficient power and serviceability during the worst combination of loads and peak conditions. In addition, it is very sensitive to changes in load and environmental conditions, and can be misapplied if not used correctly.
In the limit state method, the strength of the material and the stresses in the member are not considered. This method is used to determine the failure load of a member. The working stress method is based on the strength of the material and the stresses in the member. This method is used to determine the safe load of a member.
The limit state method of design is a more advanced and accurate method than the working stress method. The working stress method simply uses a factor of safety to determine the strength of a material, while the limit state method uses a more sophisticated analysis that takes into account the yeild strength of the material. The limit state method is therefore a more accurate and reliable method of design, and is therefore the preferred method.