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51.
In this article, a one-dimensional and a two-dimensional approach to the evaluation of local diffusion coefficients for Norway
spruce sapwood from measured moisture content (MC) values are presented. A studied wood sample was dried from the initial
green condition to about 15% mean MC, but here only the diffusive part of the drying process between approximately 25% and
15% mean MC was treated. Measured local MC values were based on nondestructive X-ray computed tomography data. Finite element
calculations were performed with two alternative diffusion coefficients to test the appropriateness of the diffusion coefficients
that were evaluated from the measured MC values. The evaluated diffusion coefficients show interesting dependence on MC and
distance from the evaporation surface. The advantage of using the methods presented is that the diffusion coefficient is calculated
on a local level without having to define a function for the diffusion coefficient’s dependency on other parameters. 相似文献
52.
The simulation analysis of temperature field under ideal condition can reflects the rule of true temperature field, but accidental factor during construction process will result in difference of the result. This paper studied the Baise RCC Dam with the distributed optical fiber technology and FEM technology, the numerical results were modified with the testing data and the contrastive curves can be obtained for the testing data,ideal simulation data and real -time simulation data. The results indicate that the modified real - time simulation can reflect the true temperature field ; it may serve as a guide for the temperature control. 相似文献
53.
With the problem of the city development, it becomes very important and urgent to research the utilization of the urban underground space. The authors discuss the interaction of high buildings and tunnel which belongs to a project at Dadukou region in Chongqing. The authors simulate this condition in computer and analyses the stress around the tunnel and find the rang of stress concentration. At last,the authors offer some references for underground-space opening of the tunnel under high buildings. 相似文献
54.
Xia Zhengzhong Luo Laian 《保鲜与加工》1992,(4)
In this paper, the finite element method(FEM) is carried out for the contact pressure under circular foundation with visco-elastoplastic model and a 8 node finite element program determing parameter. In order to prove the reliability of the theoretical analysis, a circular rigid loading plate test on remolded clay is done. Otherwise, a comparison of the measuring contact pressure under box foundations of highrise buildings in Beijing and Shanghai with the calculated value by different method is made. The result shows the calculated value by the method proposed in this paper is more coincident with practical data. 相似文献
55.
使用空间轴对称有限元方法,将稻谷颗粒视为由3种材料组成的3层旋转椭球体,在不同初始湿度M0、温度T和相对湿度RH条件下,对内部的湿度M、温度T进行了数值模拟,应用所得结果对吸湿应力场进行了数值计算,分析了胚乳中截面的应力分布随时间的变化。计算结果表明,接伸应力峰值出现在谷粒中心,垂直于中截面,由于此峰值应力对裂纹的产生有直接的影响。西方着重研究了M0、RH和颗粒吸湿量对中心轴向应力峰值及其出现时间 相似文献
56.
In order to reflect the stochastic characteristic of a structure more completely and accurately,this paper presents a theory and method of modeling with structural stochastic parameters using probabilistic finite element method and perturbant finite element method,on the basis of modeling with deterministic parameters.It is applied to double decker space frame,good results are gained. 相似文献
57.
58.
59.
伴热管道传热性能的有限元分析 总被引:5,自引:1,他引:5
对伴热管的伴热效果进行了有限元分析.研究结果表明,为保证伴热管的伴热效果,在伴热管施工过程中保持伴热管和工艺管的紧密接触是十分重要的,一旦伴热管和工艺管道间存在微小间隙时,伴热管的伴热效果将快速下降. 相似文献
60.
陆林广 《扬州大学学报(农业与生命科学版)》1989,(2)
为适应具有自由面的二维流动问题中流动区域不能预先给定的特点,本文应用有关y函数的理论,推导了映象平面内不可压缩理想流体关于y函数的定常流动有限元方程,并介绍了驼峰溢流堰过堰流动问题的有限元解算例。 相似文献