Maximum debond length

The instability condition requires that the derivative of the partial debond stress with respect to the remaining bond length z = L — j k equal to or less than zero, i.e., dtr /dz O (Kim et al., 1991). Therefore, the fiber debond process becomes unstable if L - t) is smaller than a critical bond length, Zmax. where the slopes of the curves become zero in Figs. 4.23 and 4.24. At these bond lengths, the partial debond stress, maximum debond stress, crj. The Zmax value is determined from Eq. (4.102) as... 

Similarly, the initial debond stress, oq, is obtained for the infinitesimal debond length, the maximum debond stress, debond length becomes = L - Zmax and the post-debond initial friction pull-out stress, [Pg.153]

Fig. 4.39. Comparisons of initial debond stress,

Less debonding length between CFRP plates and concrete at mid-span Higher maximum load. 

The most simple chain lenght distribution is the delta function or the monodisperse distribution w)=<5(w-wa). All chain lengths are equal to wa.The maximum of S is reached just prior to debonding, i.e. for wc=wa... 

Zmax maximum embedded fiber length for unstable debond process... 

Here, T = maximum load measured prior to debonding of the fibre, d=diameter of used fibre, and I=length of embedded portion of fibre. 

In the case of a debonding involving the first layers of the masonry and with anchor lengths equal to or larger than the optimum length, the factored tensile stress within the reinforcement, that is, the value of the maximum tensile stress at which the reinforcement can work on the ends of the anchor section, once the transfer of stresses from the masonry to the FRP reinforcement has taken place, is as follows ... 

After the maximum adhesional shear stress has been exceeded, debonding will initiate and gradually develop along the entire fibre length, without... 

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