摘要
采用原位悬臂梁方法对内蒙古乌梁素海淡水冰层进行弯曲强度与弹性模量测定。应用材料力学理论,在假设冰层为均质各向同性材料;梁的根部刚性连接;没有水浮力支承条件下,计算冰层弯曲强度与弹性模量。同时试验时冰层温度垂直剖面。首先用冰层中间处温度,建立弯曲强度和弹性模量与冰温之间的初始关系;然后将冰温垂直剖面分布式带入弹性模量与冰温的初始关系式中,得到弹性模量垂直剖面,据此确定冰层弯曲破坏时中性轴的近似位置。在利用中性轴近似位置处冰温,再次建立弹性模量与冰温之间的关系,利用迭代思想确定更加精确的中性轴位置。迭代四次之后,得到中性轴精确位置。将中性轴精确位置处的冰温作为冰层的等效温度,并依次建立弯曲强度和弹性模量同等效冰温的试验关系。分析结果表明,温度从-1.831℃到-7.726℃,弯曲强度在436.12kPa到750.31kPa之间,弹性模量在3.62GPa到6.71GPa之间。它们的总体走势是随着冰温的降低,弯曲强度和弹性模量呈现增加趋势。
Experiments on Flexural Strength and Elastic Modulus of natural freshwater of Ulansuhai Lake in Inner Mongolia were conducted by in situ cantilever beam method.Applying the mechanics of materials method,under the conditions of assuming that the ice is homogeneous and isotropic,the rear of beam is rigidly connected,and there is no water buoyancy supported,the flexural strength and elastic modulus of ice sheet and ice sheet temperature vertical profile were calculated.First,the initial relationship between bending strength,elastic modulus and ice temperature in the middle of ice cantilever was established.Then the formula of the ice temperature vertical profile was brought into the initial relationship between the elastic modulus and the ice temperature,and then the elastic modulus vertical profile distribution was available.According to this,the approximate position of the neutral axis was determined when the ice had flexural failure.Using ice temperature at the approximate position of the neutral axis,the relationship between the elastic modulus and the ice temperature was established again.The more accurate position of the neutral axis could be determined by the iteration method.After four iterations,the position of the neutral axis was accurate.The ice temperature at the precise location of the neutral axis was used as the equivalent temperature of the ice layer.The experimental relationship between bending strength,elastic modulus and equivalent ice temperature was established.Analysis results showed that the temperature ranged from 1.831 ℃to 7.726 ℃,the flexural strength ranged from 436.12 kPa to 750.31 kPa and the elastic modulus ranged from 3.62 GPa to 6.71 GPa.The overall trends of flexural strength and elastic modulus were basically increasing with decreasing temperature.
出处
《南水北调与水利科技》
CAS
CSCD
北大核心
2016年第6期75-80,共6页
South-to-North Water Transfers and Water Science & Technology
基金
国家自然科学基金(51579028
41376186)
国家工信部高技术船舶科研计划项目(工信部联装[2013]417
工信部联装[2013]412)~~
关键词
冰层
原位悬臂梁
中性轴
温度
弯曲强度
弹性模量
ice sheet
situ cantilever beam
neutral axis
temperature
flexural strength
elastic modulus
