三聚氰胺-尿素-甲醛树脂浸渍改性对杉木压缩吸能特性的影响OA北大核心CSTPCD

In this study,Chinese fir wood was impregnated with melamine-urea-formaldehyde(MUF)resin solution with an 8%ratio,and then the quasi-static large deformation compression tests were conducted to investigate its compressive failure modes,mechanical properties,and energy absorption performance.The results were as follows:The weight percent gain of the modified wood reached 33.22%,and its anti-swelling efficiency attained 64.44%,indicating improved dimensional stability.The modification had no significant effect on the wood compression failure modes.The longitudinal failure mainly involved fiber buckling and tearing,the radial failure mainly involved layer-by-layer crushing of earlywood and latewood,while the tangential compressed wood was mostly matchstick damage.The compressive modulus of elasticity and crushing strength in modified specimen increased.Their plane stresses risen greatly in the transverse compression but decreased slightly in the longitudinal compression,and their densification strains decreased.The difference in compressive mechanical properties between longitudinal and transverse directions was reduced.The energy absorption per unit volume in the radial and tangential directions of the modified wood increased by 30%and 17%respectively,owever,both the longitudinal compression energy absorption and the maximum energy absorption efficiency decreased significantly.Low mass fraction MUF resin modification can significantly improve the dimensional stability of Chinese fir wood and reduce its energy absorption differences between longitudinal and transverse compression.