Properties and Testing of Fiber-Reinforced Polymers

Yasushi Miyano is Professor in Materials System Research Laboratory at Kanazawa Institute of Technology, Japan. His research focuses on the prediction methodology for long-term creep and fatigue lives of polymer composites. He is a fellow of the Society for Experimental Mechanics, The Society for the Advancement of Material & Process Engineering, and The Japan Society of Mechanical Engineers. He is also an honorary member of the Japan Society for Composite Materials. Masayuki Nakada is Professor in the Materials System Research Laboratory at Kanazawa Institute of Technology, Japan. He specializes in durability testing of polymer composites and the application of advanced accelerated testing methodologies. He is a fellow of The Japan Society of Composite Materials and has authored numerous studies advancing predictive methodologies for FRP materials.

• Preface xiiiPart 1 Accelerated Testing Methodology 1Introduction 11 Viscoelasticity 51.1 Introduction 51.2 Concept of Viscoelastic Behavior 51.3 Concept of TTSP 61.4 Master Curve of Creep Compliance of Matrix Resin 61.5 Generalization of TTSP for Nondestructive Deformation Properties to Static, Creep, and Fatigue Strengths of FRPs 81.6 Master Curve of Static Strength of FRP 81.7 Master Curve of Creep Strength of FRP 101.8 Master Curve of Fatigue Strength of FRP 101.9 Conclusion 122 Master Curves of Viscoelastic Coefficients of Matrix Resin 152.1 Introduction 152.2 Master Curve of Creep Compliance Based on Modified TTSP 162.2.1 Experimental Procedures 172.2.2 Reliable Long-term Creep Compliance of Matrix Resin 182.3 Simplified Determination of Long-term Viscoelastic Behavior 222.3.1 Relation Between Storage Modulus and Creep Compliance 222.3.2 Formulation of Master Curve of Creep Compliance 222.3.3 TTSP Automatic Shifting Procedure 242.3.4 Experimental Procedures 242.3.5 Master Curve of Storage Modulus by DMA 252.3.6 Comparison of Master Curves of Creep Compliance 272.4 Master Curve of Relaxation Modulus by DMA and Creep Tests 282.4.1 Determination Procedure of Relaxation Modulus of Matrix Resin 282.4.2 Master Curve of Relaxation Modulus of Epoxy Resin 322.5 Conclusion 333 Nondestructive Mechanical Properties of Fiber-reinforced Polymers 353.1 Introduction 353.2 Rule of Mixture 353.3 Mechanical and Thermal Properties of Unidirectional CFRPs, Fibers, and Matrix Resins 373.4 Master Curves of Creep Compliance of Matrix Resin 373.5 Conclusion 394 Static and Fatigue Strengths of Fiber-reinforced Polymer 414.1 Introduction 414.2 Experimental Procedures 414.2.1 Preparation of Specimens 414.2.2 Test Procedures 424.3 Results and Discussion 444.3.1 Master Curve of Static Strength 444.3.2 Master Curve of Fatigue Strength 464.3.3 Characterization of Fatigue Strength for Loading Directions of Three Kinds 514.4 Applicability of TTSP 534.5 Conclusion 535 Application 1 of Accelerated Testing Methodology: Static and Fatigue Flexural Strengths of Various Fiber-reinforced Polymer Laminates Under Water Absorption Condition 575.1 Introduction 575.2 Specimen Preparation 575.3 Experimental Procedures 595.4 Creep Compliance 605.5 Flexural Static Strength 605.6 Flexural Fatigue Strength 685.7 Conclusion 776 Application 2 of Accelerated Testing Methodology: Life Prediction of Carbon-fiber-reinforced Polymer/Metal Bolted Joint 796.1 Introduction 796.2 Experimental Procedures 796.2.1 Preparation of CFRP/Metal Bolted Joints 796.2.2 Tensile Static and Fatigue Tests 816.3 Results and Discussion 826.3.1 Master Curves of Creep Compliance for Transverse Direction of Unidirectional CFRP Laminates 826.3.2 Load–elongation Curves at Tensile Static Tests for CFRP/Metal Bolted Joint 846.3.3 Master Curves of Static Failure Load for CFRP/Metal Bolted Joint 856.3.4 Master Curves of Fatigue Failure Load for CFRP/Metal Bolted Joint 876.3.5 Fracture Appearance of CFRP/Metal Bolted Joints Under Static and Fatigue Loadings 916.4 Conclusion 94Part 2 Advanced Accelerated Testing Methodology 95Introduction 957 Formulation of Static Strength of Fiber-reinforced Polymers 977.1 Introduction 977.2 Formulation of Static Strength 987.3 Application of Formulation 997.3.1 Experimental Procedures 997.3.2 Preparation of Specimens 997.3.3 Test Procedures 1007.4 Results and Discussion 1027.4.1 Master Curve of Creep Compliance for Matrix Resin 1027.4.2 Master Curve of Tensile Static Strength for Matrix Resin 1047.4.3 Master Curves of Three Kinds of Static Strengths of Unidirectional Cfrp 1067.5 Conclusion 1108 Formulation of Fatigue Strength of Fiber-reinforced Polymer 1138.1 Introduction 1138.2 Formulation 1138.3 Application of Formulation 1148.3.1 Specimens and Test Methods 1148.3.2 Creep Compliance of Matrix Resin 1158.3.3 Master Curves of Static and Fatigue Strengths for Unidirectional CFRP Laminates 1178.4 Conclusion 1239 Formulation of Creep Strength of Fiber-reinforced Polymer 1259.1 Introduction 1259.2 Formulation 1259.3 Application of Formulation 1279.3.1 Specimens and Test Methods 1289.3.2 Creep Compliance of Matrix Resin and Static Strength of CFRP Strand 1289.3.3 Creep Failure Time of CFRP Strand 1309.4 Conclusion 13110 Application 1 of Advanced Accelerated Testing Methodology: Static Strengths in Various Load Directions of Unidirectional Carbon-fiberreinforced Polymer Laminates Under Water Absorption Condition 13310.1 Introduction 13310.2 Experimental Procedures 13310.3 Viscoelastic Behavior of Matrix Resin 13410.4 Master Curves of Static Strengths for Unidirectional CFRP Laminates 13710.5 Relation Between Static Strengths and Viscoelasticity of Matrix Resin 14210.6 Conclusion 14411 Application 2 of Advanced Accelerated Testing Methodology: Life Prediction of Carbon-fiber-reinforced Polymer Structures 14511.1 Introduction 14511.2 Procedure of MMF/ATM 14511.3 Determination of MMF/ATM Critical Parameters 14711.3.1 Long-term Static and Fatigue Strengths of Unidirectional CFRP Laminates 14711.3.2 MMF/ATM Critical Parameters of Unidirectional CFRP Laminates 14811.4 Life Determination of CFRP Structure Based on MMF/ATM 14911.5 Experimental Confirmation for OHC Static and Fatigue Strengths of CFRP QILs 15211.6 Conclusion 15412 Application 3 of Advanced Accelerated Testing Methodology: Effect of Molding Condition on Statistical Static and Creep Strengths of Carbon-fiber-reinforced Polymer Strand 15512.1 Introduction 15512.2 Experiments 15512.3 Creep Compliance of Matrix Resin and Static Strength of CFRP Strand 15812.4 Master Curves of Statistical Static and Creep Strengths of CFRP Strands 16112.5 Conclusion 16313 Application 4 of Advanced Accelerated Testing Methodology: Effect of Carbon Fiber on Statistical Static and Creep Strengths of Carbon-fiberreinforced Polymer Strand 16513.1 Introduction 16513.2 Molding of CFRP Strands and Testing Methods 16513.3 Results and Discussion 16613.3.1 Creep Compliance of Matrix Resin and Static Strength of Carbon Fibers 16613.3.2 Static Tensile Strengths of CFRP Strands at Various Temperatures 16713.3.3 Static Tensile Strength of CFRP Strand Against Viscoelastic Compliance of Matrix Resin 16913.3.4 Master Curves of Static Tensile Strength for Various CFRP Strands 17113.3.5 Experimental and Predicted Statistical Creep Failure Times for Various CFRP Strands 17213.3.6 Fractographs Obtained After Static and Creep Tests 17513.4 Conclusion 177Part 3 Integrated Accelerated Testing Methodology 179Introduction 17914 Integrated Accelerated Testing Methodology 18114.1 Introduction 18114.2 Formulation 18114.2.1 Viscoelasticity of Matrix Resin 18214.2.2 General Formulation of CFRP Strength 18514.2.3 Formulation of Static and Creep Strengths 18514.2.4 Formulation of Fatigue Strength 18714.3 Application of Integrated ATM 18914.3.1 CFRP Strand and Testing Method 18914.3.2 Master Curve of Relaxation Modulus of Matrix Resin 19014.3.3 Static Strength of CFRP Strand 19214.3.4 Creep Strength of CFRP Strand 19414.3.5 Fatigue Strength of CFRP Strand 19514.4 Statistical Long-term Life Prediction of CFRP Strand 19814.5 Conclusion 19915 Application 1 of Integrated Accelerated Testing Methodology: Statistical Creep and Fatigue Lives of Unidirectional Carbon-fiberreinforced Polymer Laminates Under Bending Load 20115.1 Introduction 20115.2 Experiments 20115.3 Results and Discussion 20315.3.1 Relaxation Modulus and Loss Tangent of the Matrix Resin 20315.3.2 Statistical Flexural Static Strength of Unidirectional CFRP Laminates 20615.3.3 Relation Between Flexural Static Strength of CFRP Laminates and Viscoelastic Modulus of the Matrix Resin 20715.3.4 Statistical Flexural Static Strength Versus Failure Time 20815.3.5 Statistical Flexural Creep Strength Versus Failure Time 20915.3.6 Statistical Flexural Fatigue Strength Against Number of Cycles to Failure for CFRP Laminates 21015.3.7 Fractographies After Static, Constant, and Cyclic Bending Loads 21215.3.8 Long-term Prediction of Flexural Creep and Fatigue Strengths of Unidirectional CFRP Laminates 21315.4 Conclusion 21416 Application 2 of Integrated Accelerated Testing Methodology: Carbon Fiber and Matrix Resin Mechanical Properties Controlling Statistical Tensile Fatigue Life of Unidirectional Carbon-fiber-reinforced Polymer 21716.1 Introduction 21716.2 Formulations 21716.2.1 Formulations of Fatigue Strength of Unidirectional CFRP 21716.2.2 Fatigue Degradation Parameter for Unidirectional CFRP 21916.3 Experiments 22216.3.1 Test Materials 22216.3.2 Testing Method and Test Conditions 22216.4 Results and Discussion 22416.4.1 Viscoelastic Coefficients of Epoxy Resin 22416.4.2 Static Strength of CF/EP Strands Using Three Types of Carbon Fiber 22416.4.3 Tensile Fatigue Strengths of Three Types of CF/EP Strands 22816.4.4 Influence of Strain Ratio on Tensile Fatigue Strength of CF/EP Strands 22916.4.5 Influence of Matrix Resin Viscoelasticity on Tensile Fatigue Strength of CF/EP Strands 22916.4.6 Influence of Mechanical Properties of Carbon Fibers on CF/EP Strand Fatigue Strengths 23216.4.7 Long-term Fatigue Life of CF/EP Strands 23616.5 Conclusion 23717 Application 3 of Integrated Accelerated Testing Methodology: Influence of Mechanical Properties of Carbon Fiber on Statistical Creep and Fatigue Lives of Carbon-fiber-reinforced Polymer Strands with Thermoplastic Epoxy Resin as Matrix 23917.1 Introduction 23917.2 Experimental Procedure 23917.2.1 Specimen Preparation 23917.2.2 Static, Creep, and Fatigue Tests of CF/TPEP Strands 23917.3 Results and Discussion 24117.3.1 Relaxation Modulus of TPEP Resin 24117.3.2 Static Strength of CF/TPEP Strands with Two Types of Carbon Fibers 24217.3.3 Creep Strength of CF/TPEP Strands with Two Types of Carbon Fibers 24417.3.4 Fatigue Strength of CF/TPEP Strands with Two Types of Carbon Fibers 24517.3.5 Influence of Mechanical Properties of Carbon Fibers on Creep and Fatigue Strengths of CF/TPEP Strands 24717.3.6 Creep and Fatigue Lives of CF/EP Strands and Their Comparison with CF/TPEP Strands 24917.4 Conclusion 25318 Application 4 of Integrated Accelerated Testing Methodology: Statistical Tensile and Flexural Creep and Fatigue Lives of Unidirectional Carbon-fiber-reinforced Polymer Laminates with Polypropylene as Matrix 25518.1 Introduction 25518.2 Experimental Procedure 25518.2.1 Specimen Preparation 25518.2.2 Test Methods and Test Conditions for CF/PP Laminates 25518.3 Results and Discussion 25618.3.1 Relaxation Modulus of Matrix Resin 25618.3.2 Statistical Tensile and Flexural Static Strengths of CF/PP Laminates 25918.3.3 Statistical Tensile and Flexural Creep Strengths of CF/PP Laminates 26118.3.4 Statistical Tensile and Flexural Fatigue Strengths of CF/PP Laminates 26418.3.5 Long-term Prediction of Tensile and Flexural, Creep and Fatigue Strengths of CF/PP Laminates 26718.4 Conclusion 26819 Application 5 of Integrated Accelerated Testing Methodology: Prediction of Creep Failure Life for Unidirectional Carbon-fiber-reinforced Polymer with Heat-resistant Epoxy Resin as Matrix Exposed to High Temperature Under Tension Load 27119.1 Introduction 27119.2 Experiments 27219.2.1 Specimens 27219.2.2 Testing Method 27219.2.3 Heat Degradation Treatments 27319.3 Results and Discussion 27619.3.1 Relaxation Moduli of Virgin and Heat-degraded Resins 27619.3.2 Static Strengths of Virgin and Heat-degraded CFRP Strands at Various Temperatures 27819.3.3 Statistical Creep Failure Times of Virgin and Heat-degraded CFRP Strands 28019.3.4 Long-term Prediction of Statistical Creep Strength for Heat-degraded CFRP Strands 28219.4 Conclusion 28220 Application 6 of Integrated Accelerated Testing Methodology: Effects of Annealing on Statistical Creep Life for Carbon-fiber-reinforced Polymer Strands with Thermoplastic Epoxy Resin as Matrix 28520.1 Introduction 28520.2 Formulations 28520.2.1 Matrix Resin Viscoelasticity 28520.2.2 Effect of Annealing on Matrix Resin Viscoelasticity 28720.2.3 Statistical Static and Creep Strengths of CFRP 28720.3 Experimental Procedures 28920.4 Results and Discussion 29020.4.1 Master Curve of the Relaxation Modulus of TPEP 29020.4.2 Statistical Static Strength of CF/TPEP Strands 29120.4.3 Statistical Creep Strength of CF/TPEP Strands 29320.4.4 Progress of Annealing of TPEP During the Operating Process 29420.4.5 Statistical Creep Strength of CF/TPEP Strands Attributable to Annealing Progress During the Operating Process 29520.5 Conclusion 296Appendix A: Effect of Physical Aging on the Creep Deformation of an Epoxy Resin 297Appendix B: Reliable Test Method for Tensile Strength in Longitudinal Direction of Unidirectional Carbon-fiber-reinforced Polymers 307Appendix C: Size Dependence on Tensile Strength for Resin-impregnated Carbon Fiber-reinforced Polymer Strands 317Index 327