本文選題：木質(zhì)功能材料 + 溫壓成形��； 參考：《中南林業(yè)科技大學(xué)》2017年碩士論文

【摘要】：自二戰(zhàn)以來(lái)隨著新技術(shù)革命的興起,石化資源被過(guò)度開(kāi)采、森林資源與植被遭到嚴(yán)重破壞,木材匱乏國(guó)度不計(jì)其數(shù),高值清潔利用農(nóng)林剩余物等廉價(jià)資源制備木質(zhì)功能復(fù)合材料是緩解資源、環(huán)境問(wèn)題的有利手段。本文以速生白楊剩余物為基材,在研究木質(zhì)功能材料原料粉末基本性能及其溫壓成形工藝的基礎(chǔ)上,采用理論與實(shí)踐相結(jié)合的方法構(gòu)建了木質(zhì)功能材料溫壓成形本構(gòu)方程;采用有限元法對(duì)木質(zhì)功能材料溫壓成形過(guò)程進(jìn)行了數(shù)值模擬。研究成果可作為木質(zhì)功能材料批量生產(chǎn)工藝制訂的理論依據(jù),并可作為木質(zhì)功能材料溫壓成形機(jī)理分析及失效成因分析的理論判據(jù)。完成的主要工作如下:1)研究了木質(zhì)功能材料原料粉末的密度、壓縮性、流動(dòng)性和孔隙度等基本性能,發(fā)現(xiàn)木質(zhì)功能材料原料粉末越細(xì),其孔隙率越小、松裝密度和振實(shí)密度越大、流動(dòng)性越差、壓縮性越好,但變化趨勢(shì)不明顯。(2)在小于220℃溫度環(huán)境下,對(duì)基材楊木粉末及其溫壓壓坯與木質(zhì)功能材料進(jìn)行了熱失重分析,發(fā)現(xiàn)楊木粉末與其溫壓壓坯的熱失重處于同一水平,分別為7.26%、7.19%;木質(zhì)功能材料的熱失重率為5.01%,說(shuō)明木質(zhì)功能材料具有一定的耐候性能。(3)以木質(zhì)功能材料原料粉末粒度、成形溫度、成形壓力為影響因子,以木質(zhì)功能材料表面硬度、靜曲強(qiáng)度、內(nèi)結(jié)合強(qiáng)度、彈性模量為考查指標(biāo),對(duì)木質(zhì)功能材料溫壓成形工藝進(jìn)行了研究,獲得了最優(yōu)工藝參數(shù)組合,即:原料粉末粒度-60目、成形溫度160℃、成形壓力60MPa�；谧顑�(yōu)工藝制備的木質(zhì)功能材料微觀組織塑化充分,斷口具有明顯韌性斷裂特征,體現(xiàn)出良好的綜合性能(表面硬度77.3 kg/mm2、靜曲強(qiáng)度為78.14MPa、內(nèi)結(jié)合強(qiáng)度7.44MPa、彈性模量5.52GPa)。(4)基于川北公式和木質(zhì)功能材料溫壓成形應(yīng)力應(yīng)變?cè)囼?yàn)數(shù)據(jù),采用模擬退火優(yōu)化算法反演模型參數(shù),構(gòu)建了木質(zhì)功能材料溫壓成形過(guò)程本構(gòu)方程;通過(guò)對(duì)本構(gòu)方程的模擬,發(fā)現(xiàn)該方程能較好的描述木質(zhì)功能材料溫壓成形過(guò)程中的應(yīng)力應(yīng)變關(guān)系;借助BP神經(jīng)網(wǎng)絡(luò)法擬合木質(zhì)功能材料溫壓成形應(yīng)力應(yīng)變?cè)囼?yàn)數(shù)據(jù),預(yù)測(cè)了木質(zhì)功能材料溫壓成形本構(gòu)關(guān)系,預(yù)測(cè)結(jié)果與試驗(yàn)數(shù)數(shù)據(jù)基本吻,證明采用BP神經(jīng)網(wǎng)絡(luò)法研究木質(zhì)功能材料溫壓成形過(guò)程本構(gòu)關(guān)系切實(shí)可行。(5)借助MSC.Marc軟件對(duì)木質(zhì)功能材料溫壓成形過(guò)程進(jìn)行了數(shù)值模擬。針對(duì)壓坯溫度場(chǎng)及成形壓力與成形溫度對(duì)壓坯相對(duì)密度的影響進(jìn)行了數(shù)值模擬,發(fā)現(xiàn):壓坯溫度場(chǎng)由外及里呈遞減梯度分布;壓坯相對(duì)密度隨著壓力的增加明顯增大,當(dāng)成形壓力達(dá)到60MPa時(shí)壓坯的相對(duì)密度增幅減緩,最終趨于穩(wěn)定;壓坯相對(duì)密度從上至下單向遞減呈梯度分布;壓坯的相對(duì)密度隨成形溫度升高而增加,當(dāng)達(dá)到160℃后,其相對(duì)密度增幅明顯減小。模擬結(jié)果與單向模壓成形試驗(yàn)情況吻合。
[Abstract]:Since World War II, with the rise of new technological revolutions, petrochemical resources have been overexploited, forest resources and vegetation have been severely damaged, and there are countless countries where timber is scarce. High value clean use of cheap resources such as agricultural and forestry residues to prepare wood functional composites is a good means to alleviate the problem of resources and environment. In this paper, based on the study of the basic properties of wood functional material powder and its warm compaction forming process, the constitutive equation of wood functional material warm compaction forming was established by combining theory with practice. The forming process of wood functional material was simulated by finite element method. The research results can be used as the theoretical basis for the mass production process of wood functional materials, as well as the theoretical criteria for the analysis of warm compaction mechanism and failure cause analysis of wood functional materials. The main work accomplished is as follows: (1) the density, compressibility, fluidity and porosity of the raw powder of wood functional material are studied. It is found that the finer the powder of wood functional material, the smaller the porosity. The greater the density of loosening and the density of vibration, the worse the fluidity, the better the compressibility, but the less obvious the changing trend is.) the thermogravimetric analysis of poplar powder, its warm compacted blank and wood functional material is carried out under the temperature of less than 220 鈩，

本文編號(hào)：1927346