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131.
复合固结黏性土强度及抗裂性能的正交试验 总被引:2,自引:0,他引:2
利用正交试验设计方法,以7d无侧限抗压强度为考核指标,对用ZL-1土质固化剂、石灰、水泥作为固化材料的复合固结黏性土进行了试验设计,采用极差、方差分析方法对试验结果进行了分析。结果表明水泥是对固结土强度影响最大的因素,其次是石灰,固化剂的影响较小。在正交试验的基础上,考虑了强度、造价以及施工难度等因素,确定了固结土的优化配合比,即固化剂用量0.015%、石灰用量6%。此优化配比的7d无侧限抗压强度为1.22MPa,与传统石灰土(石灰10%)7d无侧限抗压强度基本相等。对优化配合比条件下的复合固结黏性土与传统石灰土的抗裂性能进行了对比分析,结果表明固结土的温度抗裂性能与干燥抗裂性能均优于传统的石灰稳定土。 相似文献
132.
The mechanical properties of 613 small clear specimens of 35 species (11 ring-porous hardwoods, 19 diffuse-porous hardwoods,
and 5 softwoods) were evaluated. The aim of the study was to examine indexes of wood quality that are easy to measure and
that exhibit a high correlation with bending performance and hardness that are essential properties of hardwood products.
The modulus of rigidity, dynamic modulus of elasticity, bending properties (modulus of elasticity, modulus of rupture, stress
at the proportional limit, absorbed energy, Tetmajer’s modulus), dynamic energy absorption by an impact bending test, compressive
strength parallel to the grain, shear strength, partial bearing strength, and Brinell’s hardness were measured. A high correlation
was found between dynamic modulus of elasticity and static modulus of elasticity. Bending stress at the proportional limit
was found to be approximately equivalent to the compressive strength parallel to the grain. Static energy absorption correlated
with dynamic energy absorption. Tetmajer’s modulus was found to be closely related to the ratio of the initial stiffness within
the elastic range to the secant modulus at the maximum load. A high correlation was observed between Brinell’s hardness and
partial bearing strength. The difference in the regression coefficients obtained for these correlations between the species
groups was small.
Part of this study was presented at the All Division 5 Conference of IUFRO, Taipei, October 2007 相似文献
133.
新设计一款运动型三轮汽车车架为空间管阵式车架,通过建立汽车车架结构的有限元分析模型,对车架结构进行数学离散化,进行边界条件和载荷条件的模拟,并建立车架弯曲、扭转工况的分析模型,对车架进行强度和刚度的分析,保证了车架结构、性能、安全等要求,对提高整车性能具有一定的参考价值。 相似文献
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136.
This study was designed to investigate the effects of moisture content (MC) and specific gravity (SG) on the bending strength and hardness of six wood species including Japanese cedar (Cryptomeria japonica D. Don), China fir (Cunninghamia lanceolata), western hemlock (Tsuga heterophylla), red meranti (Shorea spp.), Selangan batu (Shorea spp.), and red oak (Quercus spp.). The experimental results are summarized as follows: Effects of MC and SG on the strength (MOR), stiffness (MOE), and hardness (H
B) could be represented by a multiregression formulas. A negative correlation existed between these properties and MC, whereas a postive correlation showed between them and the SG. The changing rate of these properties induced by 1% MC changes varied with the wood species: 2.6% change in MOR was observed in Japanese cedar, China fir, western hemlock, red meranti, and Selangan batu; and 3.9% was found in red oak. For MOE, a 0.58% change was observed in Japanese cedar, China fir, and red meranti; western hemlock and Selangan batu exhibited 1.2% and red oak 2.5%. For hardness, a 1.1% change was observed in Japanese cedar, western hemlock, and red oak; red meranti and China fir exhibited 3.3%; and Selangan batu 1.8%.A part of this report was presented at the 48th annual meeting of the Japan Wood Research Society in Shizuoka, Japan, April 3-5, 1998 相似文献
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138.
指接胶合木强度与工艺的关系 总被引:2,自引:0,他引:2
本文通过对四个树种指接胶合木的强度测定,说明指接胶合木的强度与加工工艺存在着密切关系,通过实验与分析找出了影响强度降低的主要因素为加工精度,如齿形,齿长、指顶隙和涂胶均匀性等。根据胶合强度,其破坏可分为四种主要形式。本试验发现抗弯强度与弹性模量间相关性较差。随温度变化,强度和温度间满足多项式关系,并且有较好的相关性。 相似文献
139.
应用PRO/E三维造型软件和ANSYS有限元分析软件,建立了ZS1105柴油机机体的有限元模型,并对其进行结构强度的分析,找出应力集中的危险截面,得到了最佳设计方案,为该机体的改进设计提供了依据。 相似文献
140.
为确立一种对复杂形状裂纹体强度设计式的推导方法,利用正交法确定了解析条件,以回归式的形式得出了设计式。运用此方法和数次数值解析,获得了有足够精度的油缸底盖与缸体间未焊接部位的强度设计式。 相似文献