r - The Hong Kong Polytechnic University

A pply Load, P (kN)
900
800
700
600
500
400
300
200
100
FE results D1
Test results D1
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 1
Deflection, δ (mm)
Test results A2
Figure 4 Load vs. deflection curves
FE results A2
A2 Test
imperfection=1.7
D1 Test
imperfection=3
Reaction, R (kN)
700
600
500
400
300
200
100
0
R
δ (Lateral)
D1
0 1 2 3 4 5 6 7 8 9 1
Lateral deformation, δ (mm)
Figure 5 Reaction vs. Lateral deformation
A2
Local
buckling
web
(a) Stress contours (b) Equivalent plastic strain contours (c) Deformed shapes of the connection
Figure 6 Typical character of the connection
PARAMETRIC STUDY AND RESULTS
In order to study the effect of different parameters to the capacity of the web, parametric study was conducted
based on the validated FE models discussed in previous section. The parameters chosen in this study were (1)
initial imperfection of web section, (2) ratio of coped length to reduced beam depth (c/h 0 ), (3) the ratio of cope
depth to beam depth (d c /D) and (4) web slenderness (d/t w ). For a beam with large web slenderness, the critical
elastic buckling load may dominate the resistance, while the plastic capacity may dominate the resistance for
beams with small web slenderness. For the purpose of investigating the inelastic local web buckling and to
ensure the results to be within the application in practice, the web slenderness was chosen from 27.4 to 57.1.
The proposed web slenderness covered a wide range of sections according to the British Standard (2000). In this
study, four universal beam sections (UB203×133×30, UB610×305×179, UB356×171×51, and UB406×140×39)
according to the British Standard (2001) were chosen. The span length of simulated beams was assumed to be
ten times of the beam depth. The load position from the coped end of beam was approximately 1.5 times the
beam depth.
The coped depth to beam depth ratio (d c /D) was set as 0.05, 0.1 and 0.15 for all models. Based on a given beam
depth and d c /D ratio, the corresponding reduced beam depth at coped (h 0 ) for each beam sections can be
obtained. The corresponding coped length (c) for each beam sections was selected in order to achieve the coped
length to reduced beam depth ratio (c/h 0 ) to vary from 0.1 to 1.0. Based on the above parameters requirement,
the corresponding coped end geometry of each beam sections was obtained. All the variables of parametric
study are presented in Table 3.
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