Yield line of reinforced concrete slabs extreme loading for. The yieldline method of analysis the term yieldline was first coined by ingerslev, in the first ever paper to appear in the structural engineer johansen then developed the theory underpinning the method later shown that the yieldline method is an upper bound plastic analysis method. There are multiple procedures to determine the forces applied on slabs. Yield line analysis of reinforced concrete slabs with openings by dip and strike angles method article pdf available in advances in structural engineering 167. Designers generally prefer to use the formulae given by the i. Both methods use the same procedure to divide the moments so found between the middle strip and column strips of the slab and the beams if any. Chapter 1 yield line analysis for slabs effects of restrained corners corner lever is the effect of forking of the yield line before reaching the corner. Yield line analysis of rectangular slabs with central openings. Yield line analysis of slabs with covered openings dtic. The slab is supported on beams of size 225 x 500 mm spaced at 4. For example, a slab with a door in the lower left corner can be.
Once grasped, yield line theory is exceedingly easy to put into. Recognize load cases that require additional analysis beyond. Application of the yield line theory for more complex situations 8. The analysis of slabs by the yield line theory top results of your surfing the analysis of slabs by the yield line theory start download portable document format pdf and ebooks electronic books free online rating news 20162017 is books that can provide inspiration, insight, knowledge to the reader. The yield line method of analysis provides a powerful means of identifying the ultimate loadcarrying capacity of reinforced concrete slabs. These methods have been the subject of research, and are well documented although hey are of a relatively specialised nature. Grdslab concrete slab on grade analysis spreadsheet. A six storey building for a commercial complex has plan dimensions as shown in figure 1. Oneway and twoway slabs university of asia pacific. Slab analysis by using yield line method bangla lecture. The common yield surfaces of metal plates are compared with the upper yield surface, and the yield surface of the arbitrarily reinforced concrete slab is derived. It is closely related to the plastic collapse or limit analysis of steel frames, and is an upper bound or mechanism approach. Reinforced concrete slabs and yieldline analysis springerlink. One way slab with cold form steel decking as form and reinforcement 4.
Chapter 1 yield line analysis for slabs h o g g i n g y i e ld li n e. Simplified method for design or moment endplate connections. Yieldline analysis of slabs leonard leslie jones, randal. Limit analysis of rc slabs exposed to standard fires. Quintas there is a controversy about whether the classical yield lines analysis methods are in fact different methods or simply different ways to develop basically the same method. The rupture strain of reinforcement is defined in the. Department of mechanics, materials and structures english. Weak axis bending capacity, 2757 inlbft, calculated. Nonlinear analysis of reinforced concrete beams, beam. Chapter 1 9 yield line analysis of slabs 1 nust studocu. From the other hand, slabs, at most times, unless designed properly, are the main cause of failure of reinforced concrete structures. Types of slabs, design of slabs and yield line theory.
Present example problems for design with concentrated loads. Various simplified methods are therefore adopted for determining moments, shears. Yieldline theory and limit analysis of plates and slabs. Yield line theory for slab design assumptions, methods of analysis. Types of slabs, design of slabs and yield line theory different floor and roof slab types. Slab is the only commercially available software to systematically automate the wellknown yieldline analysis method for concrete slabs, allowing the ultimate load capacity and critical failure mechanism to be calculated in seconds. Modified tjs method for yield line analysis and design of slabs. This means you ignore other possible yield line patterns at your peril. This site is like a library, use search box in the widget to get ebook that you want. Reinforced concrete slabs research collection eth zurich. Automatic yieldline analysis of slabs using discontinuity layout. Steel construction institute a method is developed that allows automated lower bound analyses of concrete slabs to be carried out, with the.
It is demonstrated that the normal moment criterion usually employed in modern yieldline theory is identical with the stepped criterion of the classical theory, and that they both correspond to a yield surface, called the upper yield surface, which satisfies the. Assessment of flat deck metallic plates yield line and. Yield line design has the advantages of economy, simplicity and versatility. A yield line analysis is presented for simply supported rectangular concrete slabs isotropically reinforced with central rectangular openings, under uniformly distributed load. It uses yield line theory to investigate failure mechanisms at the ultimate limit state. Modified tjs method for yield line analysis and design of slabs orumu s. Acces pdf yield line analysis of slabs method part 3 solved examples on yield line theory. Ebook the analysis of slabs by the yield line theory as pdf.
Pdf yield line analysis of reinforced concrete slabs. This study presents a simplified method for determining the ultimate strength of moment endplate connections. Mar, 2011 however, did you know that yield line analysis is an upper bound method. Two main methods for yield line analysis of slabs valentn quintas1 abstract.
Yield line theory for slab design assumptions, methods of. One way slab supported by monolithic concrete beam 2. Specifically, a concrete slab on grade may be subjected to concentrated post or wheel loading. Dip and strike angles method for yield line analysis of. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3. The yield line method is widely used for the analysis and design of reinforced, concrete slabs. Determination of the reinforced concrete slabs ultimate. Design of steel deck for concentrated and nonuniform loading. Yield line analysis of slabs download ebook pdf, epub. The building is located in seismic zone iii on a site with medium soil. This site is like a library, use search box in the widget to get ebook that. Yield line theory, on the other hand, is an efficient way of determining the collapse load of reinforced concrete slabs, and it predates limit analysis.
Finally, the relationship between yield line theory and limit analysis is discussed, and it is. The importance of the theory is more reflected in the analysis of slabs. Introduction the yield line method is a simple and efficient method to calculate the plastic collapse load of flat, relatively thin, plates of rigidperfectly plastic material when transversely loaded in bending. Reinforced concrete design 1 design of slab examples. Behavior of slabs loaded to failure in flexure four or more stages. The three possible yield line patterns mechanisms are analyzed and design diagrams derived for rapid determination of the correct mechanism and the required. Automated lower bound analysis of concrete slabs c. Example yieldline pattern for a rectangular slab with simple.
Continuous one way slab figure 1 shows a clear area of 12 m x 8. Rajagopal, kadambi ramaswami, nonlinear analysis of reinforced concrete beams, beamcolumns and slabs by finite elements 1976. That is, the load factor at which the uls moment equals the moment capacity. Chapter 1 yield line analysis for slabs bending yield. Cc c column b beam c cc c b b b c c bb b b b b b b b b. It is a robust and proven design technique that challenges designers to use judgement. The yield analysis was proposed by ingerslev in 1923. Pdf two main methods for yield line analysis of slabs. Ultimate behavior of oneway spanning slab linear elastic analysis methods such as moment distribution are linear elastic methods. Using the dip and strike angles method of representing the geometry of yield line pattern in terms of the dip and strike angles of the deflected slab segments, the yield line analysis of reinforced concrete slabs had been successfully computerized. Click download or read online button to get examples of slab design by the yield line theory book now. A comparison is made between the load paths associated with hillerborgs advanced strip method and several alternative formulations. Strip method for slabs strip introduction text method for slabs in section 14. Feb 19, 2017 what it is the yield line method is a method for the design or assessment of concrete slabs.
The yield line theory which is an ultimate load analysis, is. Yield line and strip methods concrete design eurocode. This project presents the yield line analysis which can be used to analyze and design different shapes of slabs. Once grasped yield line design is an exceedingly powerful design tool. With a view to application in highway bridge design, the ha and hb load systems are considered. Overview the theory presented in this chapter extends the ultimate load analysis of structures, begun in chapter 18 for beams and frames, to reinforced concrete slabs. Yield line design demands familiarity with failure patterns, i. Yield line analysis of reinforced concrete slabs with.
The application of yield line theory to the ultimate load design of reinforced concrete skew slabs is considered in some detail. The yield line theory is conducted based on the bending moment of the structural element at its collapse state. Assessment of flat deck metallic plates yield line and membrane analysis boulent m. Before cracking the slab acts as an elastic plate, and for short time loads, the deformations, stresses and strains can be predicted from an elastic analysis. Efm is the most comprehensive and detailed procedure provided by the aci 318 for the analysis and design of twoway slab systems where the structure is modeled by a series of equivalent frames interior and exterior on column lines taken longitudinally and transversely through the building. Kwan the university of hong kong yield line analysis is a useful method for design of reinforced concrete slabs, but has been limited to slabs of simple. Oneway simply supported slab analysis and design of the slab similar to design of simply supported beam as indicate in the previous chapter. Oral buyukozturk design example yield line theory 1 6 massachusetts institute of technology 1. Founded in 1904 and headquartered in farmington hills, michigan, usa, the american concrete institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensusbased standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete. Reinforced concrete effective span centretocentre distance between supports longer dimension of a rectangular panel of slab for yield line calculations modular ratio esec design bending moment per unit width of slab modified to account for axial load moment per unit width about xaxis moment per unit width about yaxis. To see their result for this slab we will find the load factor.
Wager oceanfront structures division, code esc62 naval facilities engineering service center port hueneme, ca 930434328 26th dod explosives safety seminar august 1618, 1994 miami, florida abstract the yield line analysis method is used extensively throughout the blast design and. For the love of physics walter lewin may 16, 2011 duration. Automatic yieldline analysis of slabs using discontinuity. Department of civil engineering and hydrology niger delta university wilberforce island, nigeria abstract. Practical yield line design an introduction to the practical use of yield line theory in the design of economic reinforced concrete slabs, including examples of design of flat slabs, raft foundations and refurbishment. Analysis is based on rotation capacity at the yield line, i. Limitanalysis of rc slabs exposed to standard fires. What it is the yield line method is a method for the design or assessment of concrete slabs. Answers are needed, for example, for round or triangular slabs, slabs with large. Aug 08, 2014 however, the popularity of applicationspecific yield line analysis tools, for example the cobras reinforced concrete bridge assessment tool developed at the university of cambridge, and which involves automatically searching through a library of possible yield line failure mechanisms, indicates that a systematic yield line method would. For practical purposes, the ultimate moment of resistance 1 of reinforced concrete slabs may be determined by the methods explained in chapter 4 for beams. Grdslab is a spreadsheet program written in msexcel for the purpose of analysis of concrete slabs on grade.
Feasible arc interior point algorithm and six examples of reinforced concrete slabs. To this effect the following schematic sketches the resulting yield pattern at the corners. As an introductory example consider the uniformly loaded beam shown in fig. Analysis of twoway slabs by coefficient method the determination of exact moments in twoway slabs with various support conditions is mathematically formidable and not suited to design practice. Flow chart of the numerical yield line analysis program. Its value is that it accounts for redistribution of forces that take place after the slabs reinforcement yields. The theory focuses attention on the moment capacity of the slab. In this paper two methods are proposed that, without invalidating previous ones. Ebook the analysis of slabs by the yield line theory as. The yield line method of analysis provides a powerful means of identifying the ultimate load carrying capacity of reinforced concrete slabs. Yield line design is a wellfounded method of designing reinforced concrete slabs. However, the popularity of applicationspecific yield line analysis tools, for example the cobras reinforced concrete bridge assessment tool developed at the university of cambridge, and which involves automatically searching through a library of possible yield line failure mechanisms, indicates that a systematic yield line method would. The slab is without drops and is supported internally and on the external long sides by square columns.
Analysis of flat sanalysis of flat sllabab moment division example 6000 6000 6000 6000 6000 5000 layout of building 7000 5000 a floor slab in a building where stability is provided by shear walls in one direction ns. Limit analysis provides a powerful tool for treating such problems. Dip and strike angles method for yield line analysis of reinforced concrete slabs a. October 2010, italy elias yusuf ali politecnico di milano. Jul 01, 20 chapter 1 yield line analysis for slabs. Nonlinear analysis of reinforced concrete beams, beamcolumns and slabs by finite elements.
Figure 6 illustrates the fracture yield line predicted by both classical yield line theory and els. Classic yield line analysis is used to determine the connection capacity based on endplate strength, and a simplified version of the kennedy method is used to predict the connection capacity based on bolt strength with prying action. The yield line method of analysis for slabs is an upper bound method, and. Pdf yield line analysis of reinforced concrete slabs with. There is a controversy about whether the classical yield lines analysis methods are in fact different methods or simply different ways to develop basically the same method. The yield line method of analysis johansen 1943 is a longestablished and extremely powerful tool for estimating the maximum load sustainable by a reinforced concrete slab. Design of slab examples and tutorials by sharifah maszura syed mohsin example 2. If, for a small increment of displacement, the internal work done by the slab, assuming that the moment at every plastic hinge is equal to the yield moment and that boundary conditions are satisfied, is equal to the external work done by the given load for that same small increment of displacement, then that load is an upper. Since the yield line method leads to an upper bound solution, different mechanisms as well as different dimensions for each mechanism must be tried in order to find the lowest predicted strength of the plate. Click download or read online button to get yield line analysis of slabs book now. Practical yield line design 4 yield line design is a robust and proven design technique. Benefits of the yield line method are that it will often identify additional reserves of strength when applied to the analysis of existing slabs, and to highly economic slabs when used in design. The yield line theory of analysis is a factored or ultimate load method of analysis. Oral buyukozturk outline 11 limitations on yield line theory.
The effect of fixing the corners of the slab against lifting 5. The yieldline method of analysis provides a powerful means of identifying the ultimate. Yield line method applied to slabs with different supports. To apply the method successfully, traditionally users have had to know something about the rulesgoverningthe construction ofviableyield line. The usual geometrical, statical and physical conditions for the anisotropic, perfectly plastic plate are given. The equation 2 is associated to the positive yield line 16 and equation 3 is. Note the con ventions for the representation of different support conditions. Yield line analysis of slabs with covered openings by phillip c. Benefi ts of the yield line method are that it will. Jan 23, 2017 for the love of physics walter lewin may 16, 2011 duration. It is a versatile tool that challenges designers to use judgement. The two principal approaches are the yield line method, which is particularly litable for slabs with a complex shape or concentrated loading, and the strip method hich is valuable where the slab contains openings.
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