摘要
以云杉-松木-冷杉胶合木板材(SPF板材)为试验梁原材料,采用一种新型自攻螺钉加固胶合木梁的新方法(从梁底部旋入新型自攻螺钉以实现对普通胶合木梁的加固)制作了24根2850 mm(长)×50 mm(宽)×150 mm(高)的胶合木梁,进行三分点受弯试验,分析新型自攻螺钉不同的锚入深度、旋入角度和螺钉间距对胶合木梁受弯性能的影响。结果表明:新型自攻螺钉加固,可有效提高胶合木梁的极限承载能力,提高幅度在11.40%~71.40%不等,同时也可提高胶合木梁的刚度并减小跨中挠度变形,能够实现抑制和减缓胶合木梁脆性破坏。试验梁的承载能力与新型自攻螺钉锚入深度呈正相关,刚度随新型自攻螺钉锚入深度的增加呈现先增加后减小的趋势;新型自攻螺钉的螺钉间距对试验梁的极限承载能力影响不大,但对刚度有较大的影响,在螺钉间距大于1倍的梁高时,刚度与螺钉间距呈负相关;45°旋钉加固梁的极限承载能力优于垂直旋钉加固梁,同时其刚度更好,可更好地抑制和减缓试验梁的脆性破坏。推荐加固方式:梁底45°旋钉,垂直锚入深度为2/3倍的梁高,螺钉间距为1倍梁高。
With SPF(Spruce-Pine-Fir)as the test beam of raw materials,by adopting a new type of self-tapping screw glulam beams with new method(from the bottom of the beam screwing in new type of self tapping screw to achieve the common glulam beams reinforcement)made 242850 mm(length)×50 mm(width)×150 mm(high)of glulam beams,three point bending test,we studied of new type of self-tapping screw anchor depth,with screwing in different perspectives and screw spacing of glulam beams flexural performance impact.The new type of self-tapping screw can effectively improve the ultimate bearing capacity of glulam beams,increase in 11.40%-71.40%,and at the same time also can improve the stiffness of the glulam beams and reduce the midspan deflection,inhibit and slow down the brittle failure glulam beams can be implemented.Experimental beams bearing capacity and the new type of self-tapping screw anchor depth were positively correlated,stiffness with the increase of the new type of self-tapping screw anchor depth showed a trend of decrease after the first increase;New type of self-tapping screw bolt spacing of ultimate bearing capacity of the tested beam impact is not big,but has great influence to the stiffness,the screw spacing greater than 1 time the high beam,the stiffness and negatively correlated with screw spacing;the 45°rotating nail reinforcement beam’s ultimate bearing capacity is better than that of vertical spiral nail reinforcement beam,its stiffness is better at the same time,can better inhibit and slow the brittle failure of experimental beams.Recommended strengthening modes:the 45°rotating beam bottom pin,vertical anchor depth for 2/3 times high beam,screw spacing of 1 times the high beam.
作者
左宏亮
刘翰然
鲁建鑫
Zuo Hongliang;Liu Hanran;Lu Jianxin(Northeast Forestry University,Harbin 150040,P.R.China)
出处
《东北林业大学学报》
CAS
CSCD
北大核心
2020年第5期112-116,121,共6页
Journal of Northeast Forestry University
基金
黑龙江省自然科学基金联合引导项目(LH2019E005)
中央高校基本科研业务费专项资金资助项目(2572019BJ03)。
关键词
胶合木
胶合木梁
受弯性能
新型自攻螺钉
Glulam
Glued wood beams
Bending performance
New self-tapping screw
