Characterizing Mode I Fracture Behaviors of Wood Using Compact Tension in Selected System Crack Propagation

Abstract

The fracture behaviors of four wood species commonly used in wood products were characterized when subjected to compact tension (CT) load in radial-longitudinal (RL) system crack propagation. Meanwhile, the failure modes of evaluated CT samples were compared and analyzed using the fractal dimension method. The results showed that wood species had a significant effect on fracture characteristic values, including maximum fracture load, critical stress intensity factor and fracture energy. These characteristic values changed in the same way, i.e., beech wood CT samples obtained the maximum characteristic values, followed by ash, okoume, and poplar in descending order. The fracture behaviors of all wood species evaluated can be described by combining linear and exponential fitting equations at the crack initial stage and evolution stage, respectively. Linear positive proportional relationships were observed between fracture characteristic values and fractal dimensions calculated using cracks in front and left views of CT samples. However, the relationships between fracture characteristic values and fractal dimensions calculated using fracture surfaces were negative. The fractal dimensions of cracks in front view of CT samples could be a better indicator used to predict critical stress intensity factor and fracture energy, which had greater correlation coefficients beyond 0.95.

Assessment of Surface Roughness in Milling of Beech Using a Response Surface Methodology and an Adaptive Network-Based Fuzzy Inference System

“…Machines 2022, 10, x FOR PEER REVIEW 2 of 12 speed, tool angle and cutting direction [10,11], and that surface roughness is an important part for final product quality and guaranteed product commercial value [12]. Milling is the most commonly used processing method for wood machining for outstanding machining efficiency [13].…”

“…Furthermore, changes in surface roughness were investigated by Sütçü and Abdullah [9], and their study indicated that feeding speed and cutting direction are two parameters affecting surface smoothness during beech wood machining. In general, surface roughness is affected predominantly by material properties, cutting speed, tool angle and cutting direction [10,11], and that surface roughness is an important part for final product quality and guaranteed product commercial value [12].…”

Machinability of Different Wood-Plastic Composites during Peripheral Milling

“…The optimal cutting parameters determined in this study were rake angle 2 • , cutting speed 9.0 m/s, feed per tooth 0.3 mm, and cutting depth 1.5 mm. This is in contrast to traditional wood materials [20][21][22][23]. Optimal cutting parameters for WPC yielding the lowest surface roughness were determined to include a higher rake angle and cutting speed, at a lower feed per tooth and cutting depth.…”

Effects of Thermochromic Fluorane Microcapsules and Self-Repairing Waterborne Acrylic Microcapsules on the Properties of Water-Based Coatings on Basswood Surface

“…As a natural polymer heterogeneous composite material [1], wood has always been favored by people and has always maintained an important position in the field of building decoration materials [2]. However, due to changes in environmental factors [3], wood's wet expansion and dry shrinkage [4], insufficient film toughness [5] and mismatches with the wood's interface [6], cracks appear in the film during use [7,8], which reduces the sealing performance and leads to film failure. Microcapsule technology is widely used in coatings, wood products, furniture, agriculture and so on.…”