This report summarizes information regarding the analysis of concrete systems subjected to rapid loading. Engineers will obtain an overview of the subject matter along with recommended approaches for analysis and selection of material properties. Researchers will obtain a concise source of information from leading authorities in the field conducting research and applying these concepts in practice. This report describes how, as strain rates increase above 10 \u20134 to 10 \u20133 s \u20131 , concrete in tension and compression becomes stronger and stiffer, with less prepeak crack growth and less ductile behavior in the postpeak region. The rate dependence of bond is shown to be due to local crushing around deformations of the bar and to have the same relationship to rate as compressive strength. The practical effect of this local crushing is to concentrate strains in a small number of cracks, thus lowering the overall ductility of reinforced members. Finally, it is concluded that computational models of postpeak behavior under either dynamic or static load should use a localization limiter so that strain softening into arbitrarily small regions is prevented. The models should also properly pose the equations of motion; one appropriate way to do this is to represent softening through rate dependence, such as viscoplasticity. Keywords: computational modeling; concrete-reinforcement bond; cracking; fracture energy; fracture mechanics; fracture toughness; size effect; strain rate; stress-intensity factor; stress rate.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 1<\/td>\n | CONTENTS CONTENTS <\/td>\n<\/tr>\n | ||||||
| 2<\/td>\n | CHAPTER 1\u2014 INTRODUCTION CHAPTER 1\u2014 INTRODUCTION 1.1 General 1.1 General <\/td>\n<\/tr>\n | ||||||
| 3<\/td>\n | 1.2\u2014Conceptual models 1.2\u2014Conceptual models 1.2.1 Macrolevel 1.2.1 Macrolevel <\/td>\n<\/tr>\n | ||||||
| 4<\/td>\n | 1.2.2 Mesolevel 1.2.2 Mesolevel 1.2.3 Microlevel 1.2.3 Microlevel 1.3\u2014Scope 1.3\u2014Scope <\/td>\n<\/tr>\n | ||||||
| 5<\/td>\n | 1.4\u2014Abbreviations 1.4\u2014Abbreviations CHAPTER 2\u2014 EXPERIMENTAL EVIDENCE OF RATE EFFECTS CHAPTER 2\u2014 EXPERIMENTAL EVIDENCE OF RATE EFFECTS 2.1\u2014Mode I failure: plain concrete and mortar 2.1\u2014Mode I failure: plain concrete and mortar <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | 2.1.1 Charpy impact tests 2.1.1 Charpy impact tests <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | 2.1.2 Drop-weight impact tests 2.1.2 Drop-weight impact tests <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | 2.1.3 Displacement-controlled hydraulic testing machines 2.1.3 Displacement-controlled hydraulic testing machines <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 2.1.4 Split-Hopkinson pressure bar 2.1.4 Split-Hopkinson pressure bar <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 2.1.5 Tensile wave propagation device 2.1.5 Tensile wave propagation device 2.2\u2014Failure under compressive stress 2.2\u2014Failure under compressive stress <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 2.3\u2014Mixed-mode failure 2.3\u2014Mixed-mode failure <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 2.4\u2014Bond failure 2.4\u2014Bond failure <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 2.5\u2014Concluding remarks 2.5\u2014Concluding remarks CHAPTER 3\u2014 ANALYTICAL MODELING OF STRAIN- RATE EFFECTS CHAPTER 3\u2014 ANALYTICAL MODELING OF STRAIN- RATE EFFECTS <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 3.1\u2014Models for rate dependence of fracture based on micromechanics 3.1\u2014Models for rate dependence of fracture based on micromechanics <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 3.2\u2014Rate-sensitive damage models that incorporate microcracking phenomena 3.2\u2014Rate-sensitive damage models that incorporate microcracking phenomena <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 3.3\u2014Strain-rate-dependent fracture model 3.3\u2014Strain-rate-dependent fracture model <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | CHAPTER 4\u2014 COMPUTATIONAL MODELING OF LOCALIZED FAILURE UNDER DYNAMIC LOADING CHAPTER 4\u2014 COMPUTATIONAL MODELING OF LOCALIZED FAILURE UNDER DYNAMIC LOADING 4.1\u2014Model of fracture process zone 4.1\u2014Model of fracture process zone <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 4.2\u2014Nonlocal continuum models 4.2\u2014Nonlocal continuum models <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | CHAPTER 5\u2014 SUMMARY CHAPTER 5\u2014 SUMMARY <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | CHAPTER 6\u2014 REFERENCES CHAPTER 6\u2014 REFERENCES 6.1\u2014 Referenced standard and reports 6.1\u2014 Referenced standard and reports <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 6.2\u2014Other references 6.2\u2014Other references <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" 446.4R-04: Report on Dynamic Fracture of Concrete<\/b><\/p>\n |