Historical narratives as strategic resources: analysis of the Turkish international contracting sector

The Turkish contracting sector has an enviable reputation for operating in high-risk international markets. The sector’s ability to respond to market instability could meaningfully be construed as sectoral-level capability. We aim to demonstrate how history can be mobilised in a formalised “strategy text” to create a strategic narrative on the sectoral level. The Geography of Contractors as published by the Turkish Contractors Association (TCA) ostensively portrays the strategic development of Turkish international contractors over four decades. Such quasi-historical narratives are routinely mobilised for the purposes of creating a shared memory on the sectoral level. The chosen strategy text draws from multiple narrative fragments derived from past experience to generate a strategic agenda for the future. The representation given to multiple voices reflects the pluralistic nature of strategy making praxis. The overarching strategy narrative reflects a performative intent in legitimising some practices whilst discrediting others. Narrative analysis demonstrates the way in which actors, actions and events are positioned within a plot structure, with direct implications for the enactment of future strategic practices. The findings suggest that strategic actions can only ever be identified in retrospect and that such arguments are always made with an eye on the future.     

The cumulative power of incremental innovation and the role of project sequence management

In innovation and project management studies incremental development projects are perceived as theoreticlly and organisationally uninteresting. By means of a longitudinal study of product improvement projects at an automobile firm, this paper challenges such views and shows how the cumulative impact of the studied sequence resulted in a competitive repositioning of the company's product portfolio during a financially difficult period. Project managers achieved this by transcending the separation between exploration and exploitation projects; they not only adhered to time, cost and quality goals but also tried out new ways of testing and experimenting with controversial technical ideas. The paper analyzes the intensive inter project learning that generated these ambidextrous capabilities and emphasizes that practices at the project-level need to be buttressed by expanded management learning and capability development also at the sequence level.     

内阻尼对柔性连接转子系统稳定性的影响

工作在高速柔轴下的柔性连接转子容易发生转子动力学失稳，柔性连接处内阻尼是引起失稳的主要因素。采用Kelvin-Voigt黏弹性理论建立转子柔性连接的复刚度内阻尼模型，通过Kelvin-Voigt黏弹性理论损耗因子与转子模态测试得到复刚度模型中代表内阻尼的虚部系数，应用拉格朗日方法建立柔性连接转子系统的动力学方程。结合试验结果验证了模型的合理性，研究了连接处内阻尼和减振器动力学参数对转子系统稳定性的影响。结果表明，增大柔性连接处内阻尼会极大降低转子系统的稳定性，增大减振器中的刚度系数和减小折合质量可有效提高稳定性，系统的稳定性需从连接处和减振器两方面协调设计。     

基于SolidWorks和三坐标测量仪的螺杆转子精滚刀建模与检测方法

介绍了基于SolidWorks软件的螺杆转子精加工滚刀的一种精确建模方法和利用该模型对滚刀的关键工序进行模拟验证的方法,同时介绍了在三坐标测量仪上利用螺杆转子精滚刀模型和曲线功能对螺杆转子精滚刀齿形进行检测的方法。     

基于ANSYS的脱溶机转子结构有限元分析及优化

大豆粕低温脱溶过程中,传统脱溶机转子的辐条式端板结构易出现疲劳断裂。通过对脱溶机转子辐条式端板的结构研究,建立力学模型,采用ANSYS软件对转子辐条式端板进行有限元分析,模拟辐条各截面上应力的变化,确定端板辐条应力集中位置。为该转子端板结构的改进方案提供理论依据。     

用“沸石转轮浓缩吸附+氧化燃烧”处理涂装废气的设计

从法规要求、废气初始浓度、设备、安全措施、电气控制等方面详细介绍了涂装车间采用沸石转轮浓缩吸附和氧化燃烧技术处理废气时在规划及设计过程中需注意的要点。     

A simple improvement of a tip loss model for actuator disc simulations

The loading of a wind turbine decreases towards the blade tip because of the velocities induced by the tip vortex. This tip loss effect has to be taken into account when performing actuator disc simulations, where the single blades of the turbine are not modeled. A widely used method applies a factor on the axial and tangential loading of the turbine. This factor decreases when approaching the blade tip. It has been shown that the factor should be different for the axial and tangential loading of the turbine to model the rotation of the resulting force vector at the airfoil sections caused by the induced velocity. The present article contains the derivation of a simple correction for the tangential load factor that takes this rotation into account. The correction does not need any additional curve fitting but just depends on the local airfoil characteristics and angle of attack. Actuator disc computations with the modified tip loss correction show improved agreement with results from actuator line, free wake lifting line, and blade element momentum simulations.     

注塑材料在电机转子磁钢固定中的分析与应用

为提高电机转子磁钢固定的可靠性和经济性，本文采用了转子注塑工艺来对转子磁钢进行固定。通过对注塑材料的性能分析与验证确定注塑材料的可靠性。通过对转子注塑工艺进行验证，确定了注塑工艺参数，保证了注塑工艺的可行性。     

非摆线型采油螺杆泵转子复合加工机床研制

针对现有双头螺杆泵转子线型存在的问题以及加工方法的局限性,通过研究非摆线螺杆泵转子线型形成原理,设计了非摆线型采油螺杆泵转子复合加工机床,利用立铣刀对做行星运动的工件进行包络,加工出非摆线型螺杆泵转子。根据机床的机械结构以及转子加工表面的形成运动,对转子加工机床进行了运动分析,确定了机床各轴之间的运动关系。并分析立铣刀在加工转子时所产生的截面轮廓误差,确定了误差随工件自转转速变化的关系,对非摆线型螺杆泵转子的加工提供了参考。     

25Cr2Ni4MoV锻轴制造工艺研究

对25Cr2Ni4MoV钢锻轴的冶炼、锻造、热处理工艺进行研究,并通过超声检测和力学性能检验,充分证明了其冶炼、锻造、热处理工艺的可行性。在生产实践中,成功地制造出了4支该材质的60 MW空冷发电机转子。