Figure 1.1 Advantages and disadvantages of Steel, GRP and hybrid construction
Figure 3.1 Typical location for a hybrid joint on a naval vessel (courtesy of DCN) 240.0 110.0 4.0 230.0 120.0 Balsawood FRP Skins Steel 46.0 100.0
Figure 3.2 Schematic representation of HSC specimen (mm)
100.0 240.0 20.0 100.0 100.0 6.0 4.0 4.0 Steel Steel Void FRP Pre-drilled holes in steel to allow drilling of FRP for clamping
Figure 3.4 Lay up steel for DLHC specimens (mm)
Figure 4.2 Control and span transducer differences for FORTRESS
Figure 4.4 Experimental test set up for HSC specimen
360 100
82 82
Figure 4.6 Experimental test setup for HSC bending tests
Figure 5.2 Maximum shear and Von Mises criteria
Figure 6.1a Numerical simulation of HSC with anti-bending guides straddling the balsa/steel interface
Figure 6.1b Numerical simulation of HSC with anti-bending guides supporting only the steel
Figure 6.3 Matrix whitening due to skin buckling during compressive static test of HSC – external face of joint (see figure 3.1)
Figure 6.4 Axially compressive static test results for HSC with and without anti- bending guides
Figure 6.5 Change in HSC stiffness and energy dissipation for 17%-34% UCSnom
Figure 6.7 Change in HSC stiffness and energy dissipation for 0%-86% UCSnom
Figure 6.9 Change in HSC stiffness and energy dissipation for 0%-60% UCSnom
Figure 6.11 Change in HSC stiffness and energy dissipation for 0%-77% UCSnom,
specimen 15b
Figure 6.12 Change in HSC stiffness and energy dissipation for 0%-77% UCSnom,
Figure 6.13 Fatigue life curve for HSC joint
Figure 6.15 Static test results for DLHC without CSM interface
Figure 6.17 Comparison of stiffness against deflection
Figure 6.18 Pictorial comparison of failure surfaces with (a) and without (b) CSM layer
Figure 6.19 Load-deflection curves for 4-point bend of DLHC without CSM
Figure 6.23 Comparison in stiffness change for DLHC in fatigue between 10% and 60% of UTS
Figure 6.25 Change in HSC bending stiffness with increasing fatigue crack length
Figure 6.26 Load-displacement plot for out-of-plane residual strength test, 50mm fatigue crack (see Table 6.4 for A-E information)
Figure 6.27 Failure of HSC joint in 4-point bending
Figure 6.28b Failure surface of tensile DLHC specimen, aged
Figure 6.29 Comparison of tensile load-deflection response of unaged, aged 5544 hours and aged 11592 hours
Figure 6.30 Percentage changes in failure load and failure displacement with increasing hours of ageing
Figure 6.31 Load-deflection curves for DLHC specimens in 4-point bending unaged and aged 18936 hours
Figure 6.32 Pictures of DLHC failures in 4-point bending with (18936 hrs) and without ageing
Figure 7.2 Boundary conditions for both the HSC and DLHC (mm)
Figure 7.4 Influence of initial displacement increment size on final resultant load
Figure 7.5 Finite element result compared to experimental result for HSC in compression
Figure 7.7 Location of the maximum Von Mises stress in the adhesive layer (
σ
VM≥50 MPa)Figure 7.8 Stress components in adhesive area 1 (Fig. 7.6) at steel/adhesive interface for 0.72 mm displacement
Figure 7.9 Adhesive elements with modified stiffness properties at location of maximum Von Mises stress (MPa)
Figure 7.10 Stress components present at interface of steel and adhesive with modified element properties
Figure 7.11 Von Mises stress in the GRP skins displacement where adhesive failure occurs (MPa)
Figure 7.12 Comparison between the PDM and experimental load-deflection curves
Figure 8.1 Comparison of shear stress between FEA and Allman for a single lap joint
Figure 8.3 Maximum shear, peel and Von Mises stress against adhesive thickness using Allman’s theory
Figure 8.4 Shear stress distribution with variations in adhesive thickness using Allman’s theory
Figure 8.5 Peel stress distribution with variations in adhesive thickness using Allman’s theory
Figure 8.6 Maximum shear, peel and Von Mises stress against overlap length using Allman’s theory
Figure 8.7 Shear stress distribution with variations in overlap length using Allman’s theory
Figure 8.8 Peel stress distribution with variations in overlap length using Allman’s theory
Figure 8.9 Maximum shear, peel and Von Mises stress with variations in Young’s modulus using Allman’s theory
Figure 8.10 Shear stress distribution with variations in Young’s modulus using Allman’s theory
Figure 8.11 Peel stress distribution with variations in Young’s modulus using Allman’s theory
Figure 8.12 Percentage change from baseline of stress, stiffness and weight with changing adhesive thickness from FEA
Figure 8.13 Peel stress distribution in adhesive layer with variations in adhesive thickness from FEA
Figure 8.14 Shear stress distribution in adhesive layer with variations in adhesive thickness from FEA
Figure 8.15 Percentage change from baseline of stress, stiffness and weight with changing core thickness from FEA
Figure 8.16 Percentage change from baseline of stress, stiffness and weight with changing skin thickness from FEA
Figure 8.17 Shear stress distribution in adhesive layer with variations in adhesive thickness from FEA
Figure 8.18 Peel stress distribution in adhesive layer with variations in adhesive thickness from FEA
Figure 8.19 Percentage change from baseline of stress, stiffness and weight with changing GRP/steel bondline length from FEA
a
b
Figure 8.20 Comparison of the deformation of a short (a) and long (b) bond length from FEA
Figure 8.21 Percentage change from baseline of stress, stiffness and weight with changing taper length from FEA
a
b
Figure 8.22 Lateral deflection (exaggerated) of long (a) and short (b) taper lengths from FEA
Figure 8.23 Shear stress distribution in adhesive layer with variations in taper length from FEA
Figure 8.24 Percentage change from baseline of stress, stiffness and weight with bond length to taper ratio from FEA
Figure 8.25 Shear stress distribution in adhesive layer with variations in bond length to taper ratio from FEA
Figure 8.26 Peel stress distribution in adhesive layers with variations in bond length to taper ratio from FEA