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刚架与板组合结构动力学形状优化研究 总被引:7,自引:0,他引:7
针对刚架与板组合结构动力学形状优化问题,提出一套联合运用序列二次规划 法、BFGS变尺度法及二次插值技术(一维搜索),将约束优化问题转化为无约束序 列优化问题,得到了满意的结果。算例表明本文所述方法对刚架与板组合结构的有 效性,显示了算法的工程实用性,并能够推广到其它复杂结构的动力学形状优化问 题中去。 相似文献
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本文研究了压力容器平封头在内压作用下的形状优化问题,优化目标是尽可能降低结构的应力集中,以提高疲劳寿命,响应分析采用有限单元数值解,优化方法采用递归二次规划方法,文中对常见平封头形式进行了形状优化,并对结果进行了分析和讨论。 相似文献
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惯性系统三轴测试转台内框形状优化设计 总被引:1,自引:0,他引:1
建立了惯性系统三轴测试转台内框形状优化模型和结构分析模型,采用连续体形状优化的罚函数方法进行优化设计。优化结果与理论分析一致,最优内框形状和国外转台形状相似。 相似文献
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对基于结构可靠性分析的结构优化作了简短评述。在此基础上,引入结构动特性的主要指标之一的结构固有频率,提出了一种新的结构优化形式。这种形式实质上是将可靠性优化与动力学优化有机地结合起来。本文算例表明,这种方法是可行的。 相似文献
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根据关节式曲柄连杆机构独特的运动学、动力学规律,利用UG软件所提供的表达式、规律曲线和优化等模块,给出使主、副气缸的摩擦学特性尽量保持一致的最件结构参数,并以仿真曲线的方式再现了运动学和动力学特性的变化规律。结果表明:优化结果跟现行许多发动机采用的参数比较吻合,特性曲线的形状也非常一致,主、副气缸的运动学和动力学性能在5%的差异下保持一致;具有主、副气缸运动学上最大相似性的结构参数,可使得主、副气缸的摩擦力和扭矩尽量一致及平稳性更好。 相似文献
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针对传感器优化布置(optimal sensor placement,简称OSP)问题,提出了一种新的使用深度神经网络的解决方案,并以简化的桥梁形状的桁架结构中的振动测试传感器优化为例进行了验证。首先,选择一种传统的传感器优化布置方法,对自动化生成的大量不同的桁架结构分别进行传感器优化布置计算,将所得优化布置结果在进行数据预处理后构建出深度学习方法所需要的训练集与验证集;其次,使用Python语言和深度学习框架TensorFlow设计实现与本研究问题适配的深度神经网络模型并训练;然后,随机生成了新的桁架结构参数;最后,将深度神经网络输出的传感器布置结果和传统方法的计算结果进行了比较,验证了本研究方法的有效性以及在速度上、可移植性与可扩展性方面的性能优势。 相似文献
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基于有限元分析的结构优化设计方法 总被引:7,自引:0,他引:7
提出了利用ANSYS优化分析功能对结构进行优化分析的方法,通过十杆桁架的优化分析介绍了用有限单元法解决实际问题,实现优化设计的全过程,说明了用ANSYS优化分析功能实现结构优化分析的可行性,从而为其它复杂结构的优化分析提供了新的方法和科学依据。 相似文献
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Polynomial-basis response surface method has some shortcomings for truss structures in structural optimization,concluding the low fitting accuracy and the great computational effort. Based on the theory of approximation, a response surface method based on Multivariate Rational Function basis(MRRSM) is proposed. In order to further reduce the computational workload of MRRSM, focusing on the law between the cross-sectional area and the nodal displacements of truss structure, a conjecture that the determinant of the stiffness matrix and the corresponding elements of adjoint matrix involved in displacement determination are polynomials with the same order as their respective matrices, each term of which is the product of cross-sectional areas, is proposed. The conjecture is proved theoretically for statically determinate truss structure, and is shown corrected by a large number of statically indeterminate truss structures. The theoretical analysis and a large number of numerical examples show that MRRSM has a high fitting accuracy and less computational effort. Efficiency of the structural optimization of truss structures would be enhanced. 相似文献
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The mathematical model of optimal placement of active members in truss adaptive structures is essentially a nonlinear multi-objective optimization problem with mixed variables,it is usually much difficult and costly to be solved.In this paper,the optimal location of active members is treated in terms of(0,1)discrete variables.Structural member sizes,control gains,and(0,1)placement variables are treated simultaneously as design variables.Then,a succinct and reasonable compromise scalar model,which is transformed from original multi-objective optimization,is established,in which the(0,1)discrete variables are converted into an equality constraint.Secondly,by penalty function approach,the subsequent scalar mixed variable compromise model can be formulated equivalently as a sequence of continuous variable problems.Thirdly,for each continuous problem in the sequence,by choosing intermediate design variables and temporary critical constraints,the approximation concept is carried out to generate a sequence of explicit approximate problems which enhance the quality of the approximate design problems.Considering the proposed method,a FORTRAN program OPAMTAS2.0 for optimal placement of active members in truss adaptive structures is developed,which is used by the constrained variable metric method with the watchdog technique(CVMW method).Finally,a typical 18 bar truss adaptive structure as test numerical examples is presented to illustrate that the design methodology set forth is simple,feasible,efficient and stable.The established scalar mixed variable compromise model that can avoid the ill-conditioned possibility caused by the different orders of magnitude of various objective functions in optimization process,therefore,it enables the optimization algorithm to have a good stability.On the other hand,the proposed novel optimization technique can make both discrete and continuous variables be optimized simultaneously. 相似文献
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Despite small workspace, parallel manipulators have some advantages over their serial counterparts in terms of higher speed, acceleration, rigidity, accuracy,manufacturing cost and payload. Accordingly, this type of manipulators can be used in many applications such as in high-speed machine tools, tuning machine for feeding,sensitive cutting, assembly and packaging. This paper presents a special type of planar parallel manipulator with three degrees of freedom. It is constructed as a variable geometry truss generally known planar Stewart platform.The reachable and orientation workspaces are obtained for this manipulator. The inverse kinematic analysis is solved for the trajectory tracking according to the redundancy and joint limit avoidance. Then, the dynamics model of the manipulator is established by using Virtual Work method.The simulations are performed to follow the given planar trajectories by using the dynamic equations of the variable geometry truss manipulator and computed force control method. In computed force control method, the feedback gain matrices for PD control are tuned with fixed matrices by trail end error and variable ones by means of optimization with genetic algorithm. 相似文献
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应用模块化和产品平台的思想是企业设计和开发产品族(系列)的重要策略。本文提出一种可用于产品族设计的二级优化方法。该优化方法将产品族设计优化分为二个层次:产品平台优化层次和专用模块的优化层次。为了提高这种优化方法的可靠性和减少计算量,在二级优化基本框架基础上引入了代理模型技术。将二级优化方法应用于桁架族优化设计算例,计算结果表明:基于代理模型的二级优化方法能成功地解决桁架族优化设计问题,具有很好的可靠性,而且能有效地减少产品族优化设计中计算量。 相似文献
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压电智能结构在航天、航空工程获得了广泛应用。但其在随机荷载作用下的动力特性研究目前还很薄弱,以往计算方法的复杂性是造成这一状况的重要原因。本文应用虚功原理建立机电耦合智能桁架结构动力有限元方程,并基于虚拟激励原理提出系统受平稳/非平稳随机激励动力响应的高效算法,该方法自动包含了全部参振振型之间的互相关项及全部随机激励之间的互相关项,本质上是精确解法。应用给出的算法对15杆平面及25杆空间智能桁架进行较宽频带激励下平稳/非平稳随机振动分析,计算结果表明了算法的可靠及高效性。本文的工作为进一步进行压电智能桁架机电耦合系统随机控制打下良好的基础。 相似文献