南京林业大学学报(自然科学版)
南京林業大學學報(自然科學版)
남경임업대학학보(자연과학판)
JOURNAL OF NANJING FORESTRY UNIVERSITY(NATURAL SCIENCE EDITION)
2014年
5期
25-28
,共4页
红松%大青杨%低温%弹性模量%强度
紅鬆%大青楊%低溫%彈性模量%彊度
홍송%대청양%저온%탄성모량%강도
Pinus koraiensis%Populus ussuriensis%cold temperature%MOE%strength
以红松和大青杨木材为例,研究环境温度变化(尤其是低温)对木材力学性质的影响。在气干和饱湿状态下,对标准样本进行静载荷测试,获取两种木材心材和边材件在温度为20、5、-5和-20℃时的抗弯弹性模量、抗弯强度和顺纹抗压强度,分析各参数随温度降低的变化规律。结果表明:温度是影响木材力学性质的一个重要因素,随温度降低,气干材的抗弯弹性模量、抗弯强度和顺纹抗压强度均以近似线性趋势增大;饱湿材各力学参数变化曲线则存在拐点,在-5~20℃之间,随着温度降低,各力学指标增大较慢,在-20~-5℃之间,随着温度降低,各力学指标增大较快;与气干材相比,饱湿材的各力学参数对低温响应更敏感,-20℃时饱湿材各力学参数较20℃时提高约67%,而气干材-20℃时各力学参数仅约较20℃时提高15%。
以紅鬆和大青楊木材為例,研究環境溫度變化(尤其是低溫)對木材力學性質的影響。在氣榦和飽濕狀態下,對標準樣本進行靜載荷測試,穫取兩種木材心材和邊材件在溫度為20、5、-5和-20℃時的抗彎彈性模量、抗彎彊度和順紋抗壓彊度,分析各參數隨溫度降低的變化規律。結果錶明:溫度是影響木材力學性質的一箇重要因素,隨溫度降低,氣榦材的抗彎彈性模量、抗彎彊度和順紋抗壓彊度均以近似線性趨勢增大;飽濕材各力學參數變化麯線則存在枴點,在-5~20℃之間,隨著溫度降低,各力學指標增大較慢,在-20~-5℃之間,隨著溫度降低,各力學指標增大較快;與氣榦材相比,飽濕材的各力學參數對低溫響應更敏感,-20℃時飽濕材各力學參數較20℃時提高約67%,而氣榦材-20℃時各力學參數僅約較20℃時提高15%。
이홍송화대청양목재위례,연구배경온도변화(우기시저온)대목재역학성질적영향。재기간화포습상태하,대표준양본진행정재하측시,획취량충목재심재화변재건재온도위20、5、-5화-20℃시적항만탄성모량、항만강도화순문항압강도,분석각삼수수온도강저적변화규률。결과표명:온도시영향목재역학성질적일개중요인소,수온도강저,기간재적항만탄성모량、항만강도화순문항압강도균이근사선성추세증대;포습재각역학삼수변화곡선칙존재괴점,재-5~20℃지간,수착온도강저,각역학지표증대교만,재-20~-5℃지간,수착온도강저,각역학지표증대교쾌;여기간재상비,포습재적각역학삼수대저온향응경민감,-20℃시포습재각역학삼수교20℃시제고약67%,이기간재-20℃시각역학삼수부약교20℃시제고15%。
Pinus koraiensis and Populus ussuriensis timber were used to study the influence of environmental temperature (especially low temperature) on the mechanical properties of wood in this paper. The wood specimens of two species were conducted a series of wood quality tests at air-dried and wet conditions. Then the modulus of elasticity (MOE), modulus of rupture ( MOR) and compression strength of heartwood and sapwood were obtained and analyzed at -20℃,-5 ℃, 5 ℃, and 20 ℃ temperature. The results showed that temperature was one of the important factors affecting the MOE, MOR and compression strength of wood. As temperature decreased,these mechanical parameters of air-dried wood increased linearly, but for the nonlinearly increased wet wood, these parameters decreased from 20℃ to-5℃, but in-creased fast from -5 ℃ to -20 ℃. The mechanical properties of wet wood were more sensitive to low temperature than that of air-dried wood, which of wet wood were about 67% higher at -20 ℃ than that at 20 ℃, but the corresponding value of air-dried wood only increased about 15%.