Theory of Flexural Shear, Bending and Torsion for a Thin-Walled Beam of Open Section

Aspects of the general Vlasov theory are examined separately as applied to a thin-walled channel section cantilever beam under free-end end loading. In particular, the flexural bending and shear that arise under transverse shear and axial torsional loading are each considered theoretically. These analyses involve the location of the shear centre at which transverse shear forces when applied do not produce torsion. This centre, when taken to be coincident with the centre of twist implies an equivalent reciprocal behaviour. That is, an axial torsion applied concentric with the shear centre will twist but not bend the beam. The respective bending and shear stress conversions are derived for each action applied to three aluminium alloy extruded channel sections mounted as cantilevers with a horizontal principal axis of symmetry. Bending and shear are considered more generally for other thin-walled sections when the transverse loading axes at the shear centre are not parallel to the section = s centroidal axes of principal second moments of area. The fixing at one end of the cantilever modifies the St Venant free angular twist and the free warping displacement. It is shown from the Wagner-Kappus torsion theory how the end constrained warping generates an axial stress distribution that varies with the length and across the cross-section for an axial torsion applied to the shear centre. It should be mentioned here for wider applications and validation of the Vlasov theory that attendant papers are to consider in detail bending and torsional loadings applied to other axes through each of the centroid and the web centre. Therein, both bending and twisting arise from transverse shear and axial torsion applied to each position being displaced from the shear centre. Here, the influence of the axis position upon the net axial and shear stress distributions is to be established. That is, the net axial stress from axial torsional loading is identified with the sum of axial stress due to bending and axial stress arising from constrained warping displacements at the fixing. The net shear stress distribution overlays the distributions from axial torsion and that from flexural shear under transverse loading. Both arise when transverse forces are displaced from the shear centre.

Modeling and Adaptive Neural Network Control for a Soft Robotic Arm With Prescribed Motion Constraints

This paper presents a dynamic model and performance constraint control of a line-driven soft robotic arm.The dynamics model of the soft robotic arm is established by combining the screw theory and the Cosserat theory.The unmodeled dynamics of the system are considered,and an adaptive neural network controller is designed using the backstepping method and radial basis function neural network.The stability of the closed-loop system and the boundedness of the tracking error are verified using Lyapunov theory.The simulation results show that our approach is a good solution to the motion constraint problem of the line-driven soft robotic arm.

TOC理论和Witness仿真在汽车产业链整合价值的应用

以某汽车产业链整合企业作为研究对象,以约束理论(TOC)为基础,运用约束理论五步骤法对汽车产业链整合企业进行Witness仿真优化,明显提高了此汽车产业链整合企业的利润收入,达到增加企业价值的目标。

Corporate Social Responsibility and Green Innovation-The Mediating Effect of Financing Constraints

Green innovation has become a strategic direction for the country and enterprises,and it is an important facet in achieving high-quality economic development.Whether corporate social responsibility(CSR),as a key competitive strategy for achieving sustainable economic development,can promote corporate green innovation and the path of evolution has become a hot topic of current research.This paper takes Chinese manufacturing A share listed companies as its sample and uses Stata sofware to conduct regression analysis to test the relationship between CSR,financing constraints,and green innovation,respectively.It further distinguishes the sample into different technological properties and different regions to study the degree of differentiation of the mediating effect on financing constraints.The results show that CSR can not only directly promote corporate green innovation,but that it also can further positively influence corporate green innovation by alleviating financing constraints.Financing constraints play a mediating role in the relationship between CSR and green innovation,especially in enterprises with strong innovation demand and in regions with high levels of regional economic development.The findings enrich the research perspective on the relationship between CSR and green innovation and provide realistic data support for subsequent studies.

Rheological Behavior for Polymer Melts and Concentrated Solutions——Part Ⅶ: A Quantitative Verification for the Molecular Theory of Non-linear Viscoelasticity with Entanglement Constraints in Polymer Melts

Based on the molecular theory of non-linear viscoelasticity with constrained entanglements in polymer melts, the material functions in simple shear flow were formulated, the theoretical relations between. eta((gamma) over dot), psi (10)((gamma) over dot) and shear rate ((gamma) over dot), and topologically constrained dimension number n ' and a were derived. Linear viscoelastic parameters (eta (0) and G(N)(0)) and topologically constrained dimension number (n ' a and <(<upsilon>)over bar>) as a function of the primary molecular weight (M-n), molecular weight between entanglements (M-C) and the entanglement sites sequence distribution in polymer chain were determined. A new method for determination of viscoelastic parameters (eta (0), psi (10), G(N)(0) and J(e)(0)), topologically constrained dimension number (n ', a and v) and molecular weight (M-n, M-c and M-e) from the shear flow measurements was proposed. It was used to determine those parameters and structures of HDPE, making a good agreement between these values and those obtained by other methods. The agreement affords a quantitative verification for the molecular theory of nonlinear viscoelasticity with constrained entanglement in polymer melts.

Integrating Activity-Based Costing （ABC） and Theory of Constraint （TOC） for Improved and Sustained Cost Management

Implementing effective cost management approaches has recently gained momentum due to intense competition and increasing customer demands. Moreover, effective cost management approaches have contributed to firms＇ competitive advantage in relation to cost leadership strategy. Consequently, firms have implemented contemporary cost management systems, such as activity-based management, business process re-engineering, life-cycle costing, target costing, and theory of constraint （TOC）, to enable them to become low-cost producers and compete effectively and sustain their performance. Furthermore, focusing on cost management to improve profitability has led to the integration of activity-based costing （ABC） and TOC. Therefore, the aim of this study is to review literature and discuss how integration of ABC and TOC can result in improved and sustained cost management. While these methods have different approaches in addressing cost management, treating them as complementary cost management approaches can result in improved cost management due to improved product costing, improved cost reporting, improved product-mix decisions, and improved cycle-time management. Improvement in cost management will then result in sustained cost management. Sustained cost management is further enhanced with the investment in information customer and shareholder value technology that supports cross-functional decision making to continue creating to remain competitive in the market.

Ashtekar-Kodama Gravity as a Classical and Quantum Extension of Loop Quantum Gravity

This paper presents a new theory of gravity, called here Ashtekar-Kodama (AK) gravity, which is based on the Ashtekar-Kodama formulation of loop quantum gravity (LQG), yields in the limit the Einstein equations, and in the quantum regime a full renormalizable quantum gauge field theory. The three fundamental constraints (hamiltonian, gaussian and diffeomorphism) were formulated in 3-dimensional spatial form within LQG in Ashtekar formulation using the notion of the Kodama state with positive cosmological constant Λ. We introduce a 4-dimensional covariant version of the 3-dimensional (spatial) hamiltonian, gaussian and diffeomorphism constraints of LQG. We obtain 32 partial differential equations for the 16 variables Emn (E-tensor, inverse densitized tetrad of the metric) and 16 variables Amn (A-tensor, gravitational wave tensor). We impose the boundary condition: for large distance the E-generated metric g(E) becomes the GR-metric g (normally Schwarzschild-spacetime). The theory based on these Ashtekar-Kodama (AK) equations, and called in the following Ashtekar-Kodama (AK-) gravity has the following properties. • For Λ = 0 the AK equations become Einstein equations, A-tensor is trivial (constant), and the E-generated metric g(E) is identical with the GR-metric g. • When the AK-equations are developed into a Λ-power series, the Λ-term yields a gravitational wave equation, which has only at least quadrupole wave solutions and becomes in the limit of large distance r the (normal electromagnetic) wave equation. • AK-gravity, as opposed to GR, has no singularity at the horizon: the singularity in the metric becomes a (very high) peak. • AK-gravity has a limit scale of the gravitational quantum region 39 μm, which emerges as the limit scale in the objective wave collapse theory of Gherardi-Rimini-Weber. In the quantum region, the AK-gravity becomes a quantum gauge theory (AK quantum gravity) with the Lie group extended SU(2) = ε-tensor-group(four generators) as gauge group and a corresponding covariant derivative. • AK quantum gravity is fully renormalizable, we derive its Lagrangian, which is dimensionally renormalizable, the normalized one-graviton wave function, the graviton propagator, and demonstrate the calculation of cross-section from Feynman diagrams.

基于TOC理论对铸造工序的瓶颈探寻及改善

针对某精密铸造企业面临的市场需求变化和生产规模扩大的挑战,着重探讨了产品生产的瓶颈优化问题。基于约束理论(TOC),对该企业铸造工序进行了分析,建立了适用于该企业的生产能力核算方法,探寻其当前产品瓶颈现状;首先,运用全局设备效率(OEE)及瓶颈指标等定量分析方法测算企业生产流程的瓶颈工序;其次,根据各工序在制品库存积压数量和采用快速流动法等定性分析方法进行识别,确定了瓶颈工序为熔炼浇注工序,找出影响产能的具体问题;最后提出工序优化方法及改进具体措施,为企业提高生产效率、降低成本提供一定的参考。

INTEGRAL THEORY FOR THE DYNAMICS OF NONLINEAR NONHOLONOMIC SYSTEM IN NONINERTIAL REFERENCE FRAMES

This paper establishes the integral theory for the dynamics of nonlinear nonholonomic system in noninertial reference frame. Firstly, based on the Routh equation of the relative motion of nonlinear nonholonomic system gives the first integral of the system. Secondly, by using cyclic integral or energy integral reduces the order of the equation and obtains generalized Routh equation and Whittaker equation respectively. Thirdly, derives canonical equation and variation equation and by using the first integral constructs integral invariant. And then, establishes the basic integral variants and the integral invariant of Poincare-Cartan type. Finally, we give a series of deductions.

NOETHER’S THEORY OF VACCO DYNAMICS

In this paper, we first study the latent relation between the conservative quantity and the symmetry of nonholonomic dynamical systems without any additional restrictive conditions to its virtual displacement, and then establish Noether's theorem and Noether's inverse theorem of Vacco dynamics. Lastly, we give two examples to illustrate the application of result of this paper.

Over-Constraints and a Unified Mobility Method for General Spatial Mechanisms Part 2:Application of the Principle

The pre-research on mobility analysis presented a unified-mobility formula and a methodology based on reciprocal screw theory by HUANG, which focused on classical and modem parallel mechanisms. However its range of application needs to further extend to general multi-loop spatial mechanism. This kind of mechanism is not only more complex in structure but also with strong motion coupling among loops, making the mobility analysis even more complicated, and the relevant research has long been ignored. It is focused on how to apply the new principle for general spatial mechanism to those various multi-loop spatial mechanisms, and some new meaningful knowledge is further found. Several typical examples of the genera/multi-loop spatial mechanisms with motion couple even strong motion couple are considered. These spatial mechanisms include different closing way： over-constraint appearing in rigid closure, in movable closure, and in dynamic closure as well; these examples also include two different new methods to solve this kind of issue： the way to recognize over-constraints by analyzing relative movement between two connected links and by constructing a virtual loop to recognize over-constraints. In addition, over-constraint determination tabulation is brought to analyze the motion couple. The researches above are all based upon the screw theory. All these multi-loop spatial mechanisms with different kinds of structures can completely be solved by following the directions and examples, and the new mobility theory based on the screw theory is also proved to be valid. This study not only enriches and develops the theory and makes the theory more universal, but also has a special meaning for innovation in mechanical engineering.

Transition sets of bifurcations of dynamical systems with two statevariables with constraints

Bifurcation of periodic solutions widely exists in nonlinear dynamical systems. In this paper, categories of bifurcations of systems with two state variables with different types of constraints are discussed, where some new types of transition sets are added. Additionally, the bifurcation properties of two-dimensionM systems without constraints are compared with the ones with constraints. The results obtained in this paper can be used by engineers for the choice of the structural parameters of the systems.

Discussion on Rural Finanical Problems From the Perspective of Theory of Constaint

Inadequate rural financial services and low service efficiency lead to the situation that a large sum of money flows from rural areas to urban areas through commercial banks. The situation goes against the development of rural production and causes the extreme lack of rural capital, the difficuties in loaning and the prevalence of uaurious loan. In view of the problems exsited in rural financial system, the rural financial developmental trend, rural gross production, rural financial scale and rural financial efficiency from 1983 to 2008 are empirically analyzed by using the Pagano model in endogenous growth theory. The research assumes that, rural financial scale has positive relation with rural economic output, that is to say, the expansion of rural fiancial scale can facilitate the development of rural economy; the rural financial efficiency has negative relation with rural economic development. In Chinese rural areas, the economic development still relies on the expansion of rural fianance. However, at the same time of increasing the financial scale, the efficiency of rural finance is deceasing gradually. Thus, the support of rural finance on rural economic growth lies at the low level. Therefore, in view of the basic rerequisite of rural economic development, two solutions are adopted and Japanese and Kereaon experince are used. The measures are as follows. First, conducting organization innovation through promoting new village construction and gathering dispersed farmers to form rural cooperative organization to reduce trasaction cost. Second, transforming financial support from exogeneity to endogenity and marketizing rural finance so as to effectively solve the efficiency of rural finance.

Simulation Research of the TOC-Based Cost Accounting Impacting on Organizational Performance

After introducing a new management philosophy called Theory of Constraints (TOC), Dr Eli Goldratt applied it to the field of accounting, and formed a new set of measures for cost accounting. These measures are Throughput Contribution, Inventory and Operating Expenses. This paper applied the constraint-based cost accounting to three kinds of strategies decisions including contraction, cost and market, and uses the Gedunken experiment to do a contrastive research between the cost accounting based on TOC and the full-absorption cost accounting. The experiment proves that the cost accounting based on TOC outperforms the traditional cost accounting, and greatly improves organizational performance.

基于TOC的轴加工工艺均衡优化

任何生产系统中的瓶颈工序就好比是一个链条中最薄弱的环节,它制约着生产产出,属于制造系统中“关键因素”。基于此,以配气轴工序生产现状为研究对象,提出并实施了基于TOC约束理论对配气轴加工制造工序进行动态均衡的优化方案。结合配气轴加工工艺识别出瓶颈工序,通过分析瓶颈工序作业内容,对标基准节拍,制定并实施优化方案,从而消除瓶颈工序影响,以实现工序间生产均衡并提高成品生产产量。

探讨基于TOC理论提升公立医院人才招募成功率的对策

现阶段由于招聘体系设计、流程、措施等的不完善,使得许多公立医院人力资源招录管理面临诸多瓶颈,需要提出针对性的对策来解决问题。本文引入约束理论(theory of constraints,TOC)的管理理念和方法,分析公立医院人才招募工作中的各类瓶颈(折叠因素),并提出相应改进对策,完善现代公立医院人才招募工作中的主要缺陷。

基于约束理论的公立医院固定资产精益管理研究——以宁夏R医院为例

目的为了解决公立医院固定资产管理中存在的“管不清、管不好、用不好,重采买,轻管理”等主要问题,对公立医院固定资产管理进行探索。方法以约束理论(theory of constraints,TOC)为核心指导思想,结合现状分析,借助问卷调查、实地调研等方式寻找公立医院固定资产管理问题的关键影响因素。结果以问题为导向,重点从完善制度流程、系统有效使用、管理队伍建设、健全绩效考核及创新工作机制“五个关键环节”入手,构建了公立医院固定资产精益管理体系,固定资产日常规范高效管理、制度体系不断健全、管理队伍初步建成、动态管理基本实现。结论医院探索固定资产全生命周期管理,可有效提高公立医院固定资产精细化管理水平,确保国有资产的安全完整和有效使用。

绿色投资者进入与企业绿色转型——基于融资约束与绿色创新的链式中介作用

文章基于资源编排理论,以2008—2022年沪深A股制造业上市公司为样本,考察绿色投资者进入对企业绿色转型的影响机制。研究发现,绿色投资者进入可促进企业的绿色转型,在使用工具变量法和PSM法等缓解内生性问题后,结论依然稳健。机制检验发现,绿色投资者进入可以通过优化资本配置和提升绿色创新能力显著促进企业绿色转型,并且存在“绿色投资者进入—缓解融资约束—激励绿色创新—促进绿色转型”的链式中介作用;异质性检验结果表明,绿色投资者进入对企业绿色转型的促进作用在非国有企业、西部地区和重污染企业中更加明显。

竞争约束如何塑造平台相关市场?--基于反垄断案例的质性研究

相关市场界定是平台经济领域反垄断工作的起点和难点。本文基于10个平台市场和98个传统市场的反垄断案例,采用三阶段编码方法,对比分析平台市场和传统市场中从商品的替代性到市场竞争约束的传递路径,构建平台相关市场的竞争约束作用机制模型。研究发现:第一,平台资本是竞争的主体,资本的物质载体差异产生不同的价值增殖模式,在理论上形成不同的相关市场范围。第二,在流通领域,相同的使用价值追逐有限的社会需求,竞争约束表现为商品的替代性。在生产领域,不同的生产过程追逐动态的生产力水平,竞争约束表现为企业的替代性。平台的综合功能、网络效应、产消劳动和市场结构等经济特征使商品和企业的替代性分析更加复杂。第三,市场支配地位是商品的替代性和企业的替代性丧失的结果,垄断企业通过制造市场壁垒维持市场支配地位,制定高于价值的垄断价格,实现垄断利润,因而可以通过潜在竞争者约束这种垄断的市场结构。本文丰富了马克思主义理论的应用场景,为平台经济领域反垄断实务工作提供了学理支撑。

薄壁杆件屈曲模态分析的力特征约束有限条法

整体、畸变、局部等基本变形模式的划分是条理化开展薄壁杆件工程计算的必要手段。薄壁杆件的基本变形模式传统上基于简化应力-应变关系,采用变形、应变等几何特征进行定义,不利于因应复杂化应力-应变关系。提出一套完全基于力特征和正交完备性原则的基本模式定义。与广义梁理论和约束有限条法相比,提出的整体、畸变、局部3种基本变形模式关于刚度严格正交,且完整覆盖薄壁杆件全变形域。基于该定义实现了针对薄壁杆件有限条模型的屈曲模态分解和识别。算例表明,提出的基本模式定义和屈曲模态分析方法具有开、闭口和折、曲线形截面的一致适应能力,剪应变和横向伸缩的影响在基本屈曲模式中得到合理表达,曲线形截面薄壁构件具有与多边形截面薄壁构件一致的整体、畸变和局部屈曲机理。