局部表面纳米化板抗屈曲优化设计

来源 :2014年全国固体力学学术大会 | 被引量 : 0次 | 上传用户:VBlover
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
  薄板结构是工程和生活中常见的结构之一。它具有结构轻,成本低和吸收能量高等优点,被广泛的应用于工程组合结构。而这些结构屈曲问题是人们比较关注的。薄板结构的抗屈曲设计和研究一直没有间断。通常采用局部附加结构等方法阻止向某一或某类屈曲模态的发展。注意到近些年纳米技术的迅速发展,如表面纳米技术。材料的表面纳米化会影响和改变其的力学性能,如弹性模量,屈服应力,强化模量和延性等。这些性能依赖于表面纳米化程度,包括表面纳米化深度与孪晶间距等。本文采用局部表面纳米技术,对薄板局部处理,并设计三种模型。以圆板为例,径向扇形间隔纳米化模型,环向条带环状间隔纳米化模型和片状布局纳米化模型。分析了这些模型对抗屈曲贡献的关键因素,并进行了薄板抗屈曲优化设计。具体方法是以局部表面纳米化区域的形状、尺寸和孪晶间距作为设计变量,以薄板屈曲的临界载荷作为目标函数,以其它的因素作为约束条件,如纳米化要求,边界条件和加载方式等。结果表明,经局部表面纳米化和优化的薄板可提高屈曲临界载荷。结果还发现,这种纳米化技术可控制屈曲模态的临界载荷和屈曲发展路径。或者说,针对任意阶一种屈曲模态,经特定的局部纳米化后使得该屈曲模态对应的临界载荷大大提高。同时也可以诱导屈曲模态。这种方法是一种新的诱导和控制薄板屈曲模态和屈曲发展路径思路和技术,为薄板结构的抗屈曲设计提供了原理和依据。
其他文献
In this study, three modeling experiments were designed to investigate whether nano-particles incorporated in the cement paste act as nucleation sites for C-S-H gel growth during cement hydration.The
A study was carried out, using heat flow calorimetry, XRD, FTIR and SEM imaging analysis, of different influences which were exerted by the type of polymer, on the hydration behaviors of cement pastes
C3S is a nesosilicate phase which reacts with water to give C-S-H and CH.The precipitation of these hydration products has long hampered accurate investigations of the C3S dissolution alone and most r
In this work we address the feasibility of in silico studies of the influence of superplasticizers on the microevolution of cement suspensions during early hydration based on Molecular Dynamics (MD) a
Cement is an intricate component of stable wellbores as it provides zonal isolation, mechanical reinforcement of the casing and protects casing from corrosive fluids.The focus of this research was to
For the purpose of effective use of fly-ash, which is a by-product thermal power generation, fly-ash is applied to the precasted concrete products which is substituted by a large amount of fly-ash in
Cessation of the hydration of tricalcium silicate (Ca3SiO5, C3S) has been shown to occur at a relative humidity (RH) less than 80%.However, the specific reduction in reaction rate that occurs with pro
The reaction of water with tricalcium silicate (Ca3SiO5, C3S) is the most crucial reaction which results in strength development in cementitious materials.In spite of several decades of study, details
The problem of optimizing underlying functions has been well studied in recent several years.The purpose of algorithms in this research field is to find the optimizer of the underlying problem by requ
会议
粒子群优化算法(Particle Swarm Optimization,PSO)由于其算法简单高效,已被广泛用于各种寻优问题。种群规模是PSO算法的一个重要参数,表示粒子种群中粒子的个数,种群规模大小对算法特性和计算代价影响很大,种群太小,会造成局部收敛;而种群太大,计算代价太高而且收敛速度慢。经典PSO方法中,种群大小是固定的,随着优化迭代的更新,种群中的粒子向最优点收敛,此时过大种群规模会增加
会议