共查询到19条相似文献，搜索用时 171 毫秒
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考虑剪切变形时变截面梁的弯曲和稳定 总被引：1，自引：0，他引：1
提出了考虑剪切变形时变截面梁弯曲和稳定计算的传递矩阵法。利用解析法导出了等截面梁单元弯曲和稳定的正确传递矩阵，将变截面梁划分成一系列等截面梁单元，应用传递 阵原理得到变截面梁弯曲和稳定计算的整体传递矩阵，最后，给出 了一些数值计算结果。 相似文献
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基于Matlab软件,用传递矩阵法对转子动静碰摩进行仿真计算,分析动静碰摩对转子临界转速的影响,并通过试验的方法进行验证,研究结果可为转子故障的诊断提供参考 相似文献
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本文将传递矩阵法应用于风荷载作用下高层框架结构建筑物的变形计算：计算结果表明,此方法求解精确、方法简单,适用于计算机求解,并能够加以推广来计算一系列的风荷载作用下的建筑物受力计算问题,具有实际意义。 相似文献
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一种利用普通矩阵运算求传递闭包的方法 总被引：2，自引：0，他引：2
介绍了二元关系的传递闭包的常用的求法以及关系中链的定义,并在链的基础上给出了用普通矩阵运算求传递闭包的方法,与用布尔矩阵运算求传递闭包相比,更容易让人接受。 相似文献
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梁板组合结构在工程应用的过程中会产生振动,这种振动经常是有害的。为了降低这种振动,对其振动特性的研究具有重要的意义。本文采用传递矩阵的方法对其进行振动功率流的分析,首先建立每个子结构的传递矩阵模型,然后组装成系统的整体传递矩阵。这种方法能够用系统的输入参数表达系统的各个输出变量,从而可以求得梁板系统的输入和输出功率流,进而分析了梁板结构参数的变化对功率流的影响。 相似文献
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根据传递矩阵法的基本原理及单元状态矢量之间的关系,建立变截面梁弯曲变形各节点的状态矢量计算方法。其次依据变截面梁的几何和物理条件,计算出变截面梁各节点状态矢量。 相似文献
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当前阶段采用有限元分析方法在对钢结构节点极限承载力计算时,没有考虑单个支撑柱失稳对其造成的影响,导致计算获得的节点极限承载力与实际极限承载力不符,偏于不安全。针对这种情况,提出一种基于BIM技术的装配式高层钢结构节点稳定性分析方法。运用Tekla structures进行钢结构节点建模,通过钢结构各单元的传递矩阵逐次相乘构建整体框架传递矩阵,结合整个钢结构两端的边界条件,求解获得结构的稳定承载力;对高层钢结构框架施加竖向、水平载荷,分析整个架构的受力情况,完成框架失稳性的判定。实验结果表明,所提方法计算精度较高,该结构在水平、竖向载荷作用下极限承载力系数选取2. 2较合理,破坏模式符合高层建筑的抗震原则,具有足够的安全储备。 相似文献
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本文研究了以不同计算代码的CFD和FEM软件联合使用对固体火箭发动机的喷管内流场和喷管结构的热、力耦合场进行数值模拟的方法。变量的传递主要包括流场向喷管壁面传递压力载荷,喷管壁面向流场传递边界位移载荷;流场和固体壁面通过温度、热流相等相互的热边界耦合。对某发动机喷管的实际计算表明：该耦合计算方法易于实现,计算稳定性和精度均比较好。 相似文献
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《Journal of The Franklin Institute》2022,359(8):3808-3830
Compared to the traditional single color plane based image denoising methods, the quaternion valued singular value decomposition (QSVD) exploits the relationship among different color planes. Hence, it has been applied to the color image denoising. On the other hand, compared to the non-overlapping based image denoising methods, the two dimensional real valued singular spectrum analysis (2DSSA) constructs the trajectory matrix with many elements in the matrix being overlapped. Since the 2DSSA exploits the local information within each color plane, it has also been applied to the single color plane based image denoising. However, neither these two image denoising methods can exploit the relationship among the color planes and the local information within each color plane simultaneously. Therefore, this paper proposes a two dimensional quaternion valued singular spectrum analysis (2DQSSA) based method for performing the color image denoising. Our proposed method can enjoy the advantages of both methods. However, the most critical issue for the 2DQSSA is on the selection of these 2DQSSA components. This paper finds that the optimal total number of the 2DQSSA components used for performing the reconstruction is monotonic decreasing with respect to the power of the noise in the image. Therefore, the polynomial fitting approach is proposed to model this relationship. Since the 2DQSSA based denoising method exploits the relationship among the red color plane, the green color plane and the blue color plane, the 2DQSSA based denoising method outperforms the conventional single color plane based denoising methods. Moreover, since the 2DQSSA based denoising method also exploits the local relationship within each color plane, the 2DQSSA based denoising method outperforms the non-overlapping based methods. 相似文献
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基于"呼叫指纹"的重入网识别算法及其在移动市场占有率预测中的应用 总被引：1，自引：0，他引：1
控制用户的重入网是移动运营商目前十分头疼的问题，由于重入网带来的卡号资源浪费、欠费等后果造成了运营商营销成本增加和业务收入下滑，因此控制用户的重入网是当前移动运营商十分关注的热点问题，而困扰这一问题的瓶颈在于现有重入网识别技术不够成熟．准确率低、识别时间过长，不能起到有效的控制作用。在本文中，笔者结合生产实际，对“呼叫指纹”算法进行了改进，提出了新的特征提取方法和匹配算法，提高了识别的准确率和识别速度。同时对外网用户建立了指纹档案，满足了实际生产中对转网、离网率分析和市场占有率估算的要求。Markov模型在经济市场分析和预测中的应用已经十分广泛，但大多应用是在已知转移概率矩阵的情况，对于转移概率未知的情况相关的论述很少。本文指出了文献[1]提出的计算转移概率矩阵的错误之处，并根据“呼叫指纹”识别算法给出了转移概率矩阵．并根据它进行了市场占有率的测算．在实际中取得了很好的效果。 相似文献
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Leon Y. Bahar 《Journal of The Franklin Institute》1975,299(1):33-41
The two-dimensional, plane stress problem of linear elasticity is analyzed within a state space framework. The medium considered is homogeneous and isotropic. Vlasov's mixed formulation of elasticity is used throughout. The field equations are derived in closed form, thus avoiding Vlasov's intermediate infinite series solution. Finally, all the properties of the transfer matrix are shown to follow directly from embedding the problem into a state space setting. 相似文献
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The problem factorizing (separating) the transfer function of a given SISO 3-D discrete system, ie of a system depending on three independent variables, is considered. The 3-D system is assumed to be available in its transfer function representation, which is converted to a canonical state-space model by a simple inspection procedure. Then applying state-feedback to this canonical model we choose the feedback matrix gain (under certain conditions) such that the transfer function of the closed-loop system has the desireed factorized form, ie a product of three 1-D transfer functions each one being dependent on a single variable. The method is illustrated by a nontrivial numerical example. 相似文献
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《Journal of The Franklin Institute》1987,323(2):253-266
A direct procedure is developed for the design of two-dimensional asymmetric half-plane recursive digital filters. The desired specification consists of both magnitude and linear phase (i.e. constant group delay). The performance index is specified as a weighted sum of the squared distance on the complex plane between the desired and actual transfer functions at discrete points of the frequency plane. The minimization is performed iteratively using the Davidon-Fletcher and Powell method in which the initial estimate is analytically found by solving a set of linear equations. Three examples are given to illustrate the utility of the proposed procedure. 相似文献
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A simple numerical method for computing the time domain response of linear time invariant systems described by their transfer functions is presented. The method does not require computation of transfer function poles or residues; it is not influenced by the multiplicity of poles or zeroes, nor does it require computation of the matrix exponential. Rather, it is based on a numerical method for inverting Laplace transforms. It is equivalent to very high order, absolutely stable numerical integration. Stiff systems present no problems. 相似文献
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《Journal of The Franklin Institute》1986,322(4):209-220
A mixed method of model-order reduction is introduced, which is based on the linear state-space representation of the original system. The derivation of its transfer function matrix expression uses the Leverrier algorithm and the application of well known partial-fraction expansion techniques together with the concept of dominant eigenvalues on the transfer function of the system. The method is general, relatively simple to apply and yields fairly accurate reduced-order models. As an illustration the method has been applied successfully to a tenth-order two-input two-output time-invariant linear model of a practical power system. 相似文献