Inverse Problems of the Mechanics of Thin-Walled Composite Structures

New formulations and methods for the solution of the inverse problems of thin-walled layered and reinforced shells and plates are discussed. Rational projects with regard for the requirements of nonflexural deformations in layered structural members, the given deformability of particular surfaces, the realization of a strictly momentless state, an equally stressed reinforcement, and the breaking strength of the binder at the interfaces are investigated. A brief review of the known solutions to these problems is given, and solutions to some new problems are described.     

自激振荡流热管非均匀截面强化传热实验研究

本文对自激振荡流热管的传热特性及强化传热手段进行了分析,并利用高热流连续激光作为加热手段,通过改变激光器的输出功率,对等截面和非均匀截面自激振荡流热管的传热特性进行了对比实验研究。实验结果表明,非均匀截面自激振荡流热管在满足一定的前提条件下,可以明显地起到强化传热的作用。     

演化博弈与自组织合作

主要研究复杂网络上的演化博弈.首先研究具有社团结构的无标度网络上的演化囚徒困境博弈及Newman-Watts小世界网络中异质性对合作演化的影响.然后考察了在不同合作者和作弊者初始分布配置情况下,不同的初始比例条件对合作水平的影响,且在社会网络上研究了雪堆博弈中的合作演化.进一步地,讨论了网络拓扑和博弈动力学的共同演化问题和网络上演化囚徒困境中的强化学习问题.最后给出了复杂网络上演化博弈论的未来发展方向与应用前景.     

Experimental verification of some elastic properties of unidirectional composites

The first part of the paper deals with homogenization models of unidirectional composites, in which each phase of the material is bounded by parallel cylindrical surfaces. For a GFRP with epoxy resin and glass fibres, five elastic constants for six models of the composite are calculated. In the second part, the results of strain gauge tests, photoelasticity investigations, and scanning electron inspection are discussed. With these data, some elastic constants of the composite in tension and compression are found. A comparison of experimental and analytical results is presented. Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 44, No. 2, pp. 195–206, March–April, 2008.     

爆炸载荷下RC单向简支板的能量法优化设计

由钢筋混凝土(RC)板的抗力-位移(R-y)曲线特性可知,曲线下方面积代表板 在爆炸载荷作用下可能吸收的能量. 对爆炸载荷作用下RC板的R-y曲线采用双折线模型,计 算不同配筋率的R-y曲线下方面积,面积最大时的配筋率即可定义为相应设计的最佳配筋率. 考虑材料非线性及高应变率对混凝土和钢筋强度的影响,采用分层法迭代求解抗 力-挠度(R-y)曲线. 研究结果可供受爆炸载荷的RC板优化设计借鉴.     

Viscoplastic deformation of reinforced plates with varying thickness under explosive loads

The problem of viscoplastic bending of reinforced plates with varying thickness is formulated. An original method for the integration of this initial-boundary-value problem is developed. The numerical solution is compared with an analytical solution obtained with a rigid-plastic model of an isotropic circular plate. The efficiency of the method is demonstrated by analyzing the inelastic dynamics of reinforced plates with constant and varying thickness. It is shown that the maximum residual deflections of plates can be reduced severalfold by means of rational profiling and reinforcement __________ Translated from Prikladnaya Mekhanika, Vol. 44, No. 2, pp. 85–98, February 2008.     

Kink Surfaces in a Directionally Reinforced neo-Hookean Material under Plane Deformation: II. Kink Band Stability and Maximally Dissipative Band Broadening

Stationary kinks (elastostatic shocks) are examined in the context of a base neo-Hookean response augmented with unidirectional reinforcing that is characterized by a single additional constitutive parameter for the additional fiber reinforcing stiffness. Previous work has shown that such a transversely isotropic material can support stationary kinks in plane deformation if the reinforcing is sufficiently great. If the deformation on one side of the kink involves a load axis aligned with the fiber axis, then the more general plane deformation on the other side of the kink is characterized in terms of a one-parameter family of (kink orientation, kink strength)-pairs. Here, the ellipticity status of the two correlated deformation states is shown to span all four possible ellipticity/nonellipticity permutations. If both deformation states are elliptic, then a suitable intermediate deformation is shown to be nonelliptic. Maximally dissipative quasi-static kink motion is examined and interpreted in terms of kink band broadening in on-axis loading. Such maximally dissipative kinks nucleate only in compression as weak kinks, with subsequent motion converting nonelliptic deformation to elliptic deformation. The associated fiber rotation involves three periods: an initial period of slow rotation, a secondary period of rapid rotation, and a final period of essentially constant orienation.     

杂交结构的研究进展

纤维增强塑料（FRP）在土木结构中的应用越来越广泛,是目前结构工程领域内的一个研究热点,在参阅了中,外相关研究资料的基础上,介绍国内外此领域内的研究现状及其有待进一步研究的问题。     

风险敏感度激励学习的广义平均算法

提出了一种新的算法．这个算法通过潜在地牺牲控制策略的最优性来获取其鲁棒性．这是因为,如果在理论模型与实际的物理系统之间存在不匹配,或者实际系统是非静态的,或者控制动作的可使用性随时间的变化而变化时,那么鲁棒性就可能成为一个十分重要的问题．主要工作是给出了一组逼近算法和它们的收敛结果．利用广义平均算子来替代最优算子max(或min),对激励学习中的一类最重要的算法——动态规划算法——进行了研究,并讨论了它们的收敛性,目的就是为了提高激励学习算法的鲁棒性．同时使用了更具一般性的风险敏感度性能评价体系,发现基于动态规划的学习算法中的一般结论在这种体系之下并不完全成立．