Research on the propagation of wood cracks and their fracture behavior

Author: Wang Liyu
Publisher:
Publish Date: 2004-10-01
Features: This book consists of nine chapters. Chapter 1 is an introduction, primarily exploring the theoretical foundations of wood fracture mechanics and the research progress of wood fracture mechanics both domestically and internationally, and highlighting the purpose and significance of this book. Chapter 2 introduces cracks in wood, their stress intensity factors, fracture toughness, and the relationship between the stress intensity factor and the u, v displacement fields. Chapter 3 focuses on the fracture patterns of wood during moisture absorption. This chapter conducts research on the fracture patterns of wood during moisture absorption, summarizes the crack propagation paths of different types of specimens (i.e., specimens with different crack orientations), proposes a method for determining critical loads, measures the fracture toughness of wood during moisture absorption, and summarizes the effects of moisture on it. Chapter 4 covers the fracture patterns of wood during moisture desorption. Chapter 5 discusses the influence of cracks on the mechanical properties of wood. This chapter conducts flexural strength, flexural modulus, and impact toughness tests on specimens with and without cracks, demonstrating that the mechanical strength of cracked specimens is lower than that of uncracked specimens. Chapter 6 focuses on the determination of wood's elastic constants, employing electrical measurement methods to test 12 elastic constants of wood, providing necessary parameters for the calculation of stress intensity factors in the next chapter. Chapter 7 investigates the evolution and propagation behavior of cracks in wood, utilizing the digital speckle correlation method to measure the crack propagation of wood. Chapter 8 examines the microscopic morphology of wood fracture surfaces. Chapter 9 is a conclusion, summarizing the main research findings of this study.