MMS11 Design for Fatigue and Creep in Joined Systems 30 April 2003 - - PowerPoint PPT Presentation

Measurements for Materials Systems (2001-2004)

MMS11 Design for Fatigue and Creep in Joined Systems

30 April 2003

Project outline

Evaluation of design methods for predicting deformation

and failure bolted and adhesively bonded joints

Monotonic Creep Fatigue

Development and evaluation of models for describing

deformation and failure of

Tough adhesives Fibre-reinforced laminates

Determination of model parameters for different materials Comparison of predictions with measurements using a

selected joint geometry

300 mm 15 mm 150 mm 101.6 mm 15 mm Adhesive thickness = 0.5 mm 15 mm 35 mm 50 mm 15 mm 15 mm

web base plate flange

All parameter changes were based on this starting geometry

Geometry of bonded study joint Geometry of bonded study joint

Bonding options Bonding options

Filled “Bermuda Triangle” Unfilled “Bermuda Triangle” (basic geometry)

Materials Materials

Rubber Toughened Epoxy Adhesives

XD4601 (Dow Chemicals) and DP460 (3M)

Adherends

2014 aluminium alloy GRP – UD + biaxial woven fabric/epoxy (SP Systems)

Surface Treatment

Aluminium - chromic acid etched Composite - grit blasted

Systems

Aluminium/XD4601 and GRP/DP460

Autoclave Moulding GRP Flanges Autoclave Moulding GRP Flanges

Problems: Autoclave curing + spring-back

Evaluation of models for tough adhesives

Monotonic loading

Elastic-plastic models

Von Mises Linear Drucker-Prager Exponent Drucker-Prager Cavitation

Application described in a Smart Manual

Creep loading

Model based on non-linear creep in plastics Application to FE analysis

C B A

Deformed Mesh Superimposed on Original Mesh Deformed Mesh Superimposed on Original Mesh Transverse Tension Transverse Tension

Contour Plot of S Contour Plot of S11

11 Stress at Predicted Failure Load

Stress at Predicted Failure Load (contours are shown for the adhesive region only) (contours are shown for the adhesive region only)

Full 3 Full 3-

• D Model

D Model Mesh Mesh Discretisation Discretisation, Applied Load and Supports , Applied Load and Supports

½ mesh – direct tension full mesh - transverse and 45° tension (sufficient) (necessary)

C B A

Experimental Arrangement Experimental Arrangement

Publications and reports Geometric and Material Property Effects on the Performance of Adhesive T-Joints, NPL Measurement Note MATC(MN)29. Geometric and Bolt Position Effects on the Performance of Bolted T-Joints, NPL Measurement Note MATC(MN)30. Finite Element Assessment of Geometric and Material Property Effects on the Strength and Stiffness of Bonded and Bolted Joints, NPL Report MATC(A)124. Prediction of Deformation and Failure of Rubber-toughened Adhesive Joints submitted to Int. J. Adhesion and Adhesives Smart Manual

• Deformation and Failure of Rubber-Toughened Adhesive Joints

Recent publications and reports Recent publications and reports