Shape Memory Polymer Composite Booms with Applications in Reel-Type Solar Arrays

Solar arrays are the primary energy source for spacecraft.Although traditional rigid solar arrays improve power supply,the quality increases proportionally.Hence,it is difficult to satisfy the requirements of high-power and low-cost space applications.In this study,a shape-memory polymer composite(SMPC)boom was designed,fabricated,and characterized for flexible reel-type solar arrays.The SMPC boom was fabricated from a smart material,a shape-memory polymer composite,whose mechanical properties were tested.Additionally,a mathematical model of the bending stiffness of the SMPC boom was developed,and the bending and buckling behaviors of the boom were further analyzed using the ABAQUS software.An SMPC boom was fabricated to demonstrate its shape memory characteristics,and the driving force of the booms with varying geometric parameters was investigated.We also designed and manufactured a reel-type solar array based on an SMPC boom and verified its self-deployment capability.The results indicated that the SMPC boom can be used as a deployable unit to roll out flexible solar arrays.

2008,Sporting Show Booms at the Right Time

The year of 2008 is the year of Olympic.The city of Beijing,being the host city for the game,implicates numerous potential business opportunities significantly,especially for the sporting goods industry. In china,due to the abundant labor resources,market potentials and favorable policies,the sporting goods industry has developed markedly:within more than 50 years,it

BORDER TRADE BOOMS IN TIBET——An Interview With Director Benba

Benba,38,is Director ofthe BorderTrade Bureau of the TibetAutonomous Region.Born andbrought up in Xigaze,he talkedabout booming border trade in Tibet duringmy recent interview.

Construction Booms in Lhasa

Ｃｏｎｓｔｒｕｃｔｉｏｎ Ｂｏｏｍｓ ｉｎ ＬｈａｓａＣｏｎｓｔｒｕｃｔｉｏｎＢｏｏｍｓｉｎＬｈａｓａ￥ＣＥＲＩＮＧＹＡＮＧｊＪＡＮＷｈｅｎＴｉｂｅｔｗａｓｐｅａｃｅｆｕｌｌｙｌｉｂｅｒａｔｅｄｉｎ１９５１，ｔｈｅｒｅｍｏｔｅｒｅｇｉｏｎｓｕｆｆｅｒ...

Boom Box 3爆炸机独立激发新模式应用开发与测试

随着国内外节点仪的应用,采用全节点仪采集的项目越来越多,有线地震仪的井炮激发方式已经不能完全适用于全节点采集系统,因此,针对全节点采集项目,以“去有线采集系统和无线电台通讯网络”为核心思路,开发出基于Boom Box 3爆炸机的独立激发新模式。本文通过对独立激发新模式的研发思路、放炮操作流程、炮后信息下载以及测试等各方面进行了详细介绍,最后,对基于Boom Box 3爆炸机独立激发新模式的优点进行了分析。

ARCADE 2 Spatial Roar, What Theory of Relation Reveals

The theory of Relation provides an explanation for the Arcade 2 excess. It assumes that the isotropic radio emission measured by the Arcade 2 Collaboration, which is 5 - 6 times brighter than the expected contributions from known extra-galactic sources, is the residue of an immense primitive energy of ordinary matter released by a relativistic bang almost 100 million years after the big bang, which gave the mass-energy the missing gravity to activate contraction. This relativistic bang, via a Lorentz energy transformation, would have released enormous energy held to be the source of the powerful radio noise detected by the NASA researchers. This transformation would have simultaneously triggered the formation of the first stars from dense gas and the reionization of less dense neutral gas. This departs from the idea that continuous reionization began after the formation of the first stars. We emphasize the importance of primordial magnetic fields, which would have generated significant density fluctuations during recombination and acted as a direct seed for cosmic structures. The first stars and galaxies were bathed in strong magnetic fields that gave rise to the radio microwave din (boom) discovered by Arcade 2. These intense magnetic fields alter the trajectory of charged particles zooming near the speed of light, triggering the space roar and emitting radiation that forms a synchrotron radio background. The theory of Relation offers an alternative to the Lambda-CDM cosmological model, which has become the standard model of the big bang, which leads straight to the vacuum catastrophe.

Upgrade and Renovation of Steel Billet Scalein front of High-speed Wire Furnace

This article briefly introduces the weighing device for steel billets in front of the heating furnace of the high-speed wire rod unit,and analyzes and summarizes the problems existing in the original weighing device for steel billets in production and use.Based on on-site installation conditions,design a new weighing method,match a large range weighing sensor,upgrade the automation control of the weighing device,and remotely transmit the billet weighing data to the MES system of the group.The automatic,stable,reliable,and accurate measurement of steel billet raw materials has been achieved,providing important guarantees for the accurate measurement of production line billet and product yield.

Solar sail attitude control using shape variation of booms

Active attitude control of solar sails is required to control the direction of the force generated by Solar Radiation Pressure(SRP). It is desirable to control the attitude through propellantfree means. This paper proposes a new method for attitude control of solar sails: A boom consisting of "smart" structural material can be deformed by the piezoelectric actuator, and Solar Radiation Pressure torque will be generated due to shape variation of sail membrane caused by boom deformation. The method has the advantages of simple structure, small disturbance and small additional load, and is not limited by the size of the solar sail. The case of rendezvous with the Asteroid 2000SG344 is used to verify the attitude control around the pitch and yaw axes.

Model Design and Development of a Telescopic Palm Fruit Harvester

This research paper presents a comprehensive conceptual design approach for the development of a telescopic machine system, which is portable and will provide a safe method of harvesting palm fruits. For this machine system development, the material for each component of the machine system was first selected, the boom length, maximum boom angle, force and stroke length of each hydraulic cylinder, the hydraulic pump pressure, base weight, permissible weight of the cutting system and power required were then calculated in the design analysis. Furthermore, from the calculated parameters, the model of the system was created using SolidWorks engineering software, the model was developed and tested. The result shows that the cutting time of the system for one bunch of palm fruit was longer when compared to conventional systems. It was concluded that though the machine is maintenance friendly and portable, further improvements in its design are necessary so as to develop a system that will give desirable economic output at a shorter time.

Influence of Section Size of Telescopic Boom on Stability

The telescopic boom is the main bearing force component of the crane.The rationality of the design will directly affect the performance of the machine and safety.The telescopic boom is a typical thin-walled plate and shell structure.Its main form of damage is the occurrence of buckling,resulting in decreased carrying capacity,or even a security incident.In order to meet the lifting weight and height,to ensure the stability of the telescopic boom has become a major problem of the designer.There are many factors that affect the critical load of the telescopic boom,including support method,inertia moment,length and material.When the support mode,material and length are determined,the maximum factor affecting the buckling critical load is the inertia moment.In this paper,the influence of the section size on the buckling critical load of the telescopic boom is analyzed by using the inertia moment of section method ande finite element method.And the sensitivity analysis is carried out on this basis.The results of the analysis can provide designers with design reference basis.Then a reasonable cross-sectional size can be used to improve the buckling resistance capacity of the telescopic boom.

Boom Box Ⅲ黑屏故障原因及解决方法

Boom BoxⅢ是具有自主激发功能的新一代爆炸机,在激发完成后可自动记录GPS激发时间、坐标位置及井口时间等关键激发信息。这些信息被自动记录到内部CF存储卡上,可以被重复下载供节点仪器切分数据使用,或作为炮点的质控数据。但在实际使用中,Boom BoxⅢ经常发生不明原因的黑屏故障,造成炮点激发信息丢失,不得不重新打井、补炮,给项目生产造成额外的工作量。本文基于实验结果重点分析了故障发生的原因,并和厂家合作找到了解决办法,通过优化爆炸机内部结构,加装元器件,解决了爆炸机黑屏现象。

Boom Clay蠕变特性研究

Boom Clay为比利时第三纪细密黏土沉积物,其力学性质十分复杂,尤其是其显著的蠕变特性更需进行广泛的试验和深入的理论研究。通过室内固结和三轴蠕变试验,研究不同应力水平下的蠕变特性;建立以不可恢复应变为变量的不显含时间的分离型屈服面蠕变本构模型,避免了传统显含时间项的蠕变模型在土体经历加、卸载过程等复杂工况的实际计算中,具体蠕变时间确定的难题。将所建新型蠕变模型在ABAQUS软件中实现二次开发,并通过不同蠕变参数下的基本性能检验和蠕变试验的模拟,验证了所建模型的正确性和所编程序的可靠性。

Boom黏土热-力耦合弹塑性损伤模型研究

黏土的热-力耦合本构模型研究在许多工程领域,尤其是核废料地下处置方面有着十分重要的工程意义。根据Boom黏土的在不同温度下的三轴与固结试验的结果,综合考虑了温度对黏土的强度与弹性模量的影响,在Drucker-Prager(简称D-P)帽盖模型的基础上,引入了硬化方程和热损伤、力学损伤的演化方程,建立了适用于黏土的热-力耦合弹塑性损伤本构模型。将模型在ABAQUS中进行了二次开发,根据试验结果反演得到了Boom黏土的模型参数。利用所建立的本构模型,对比利时HADES试验室中的ATLAS III现场试验进行了数值仿真,计算结果表明,模型的计算结果与现场实测的结果能较好地吻合,证明了模型的合理性。

泥岩各向异性热-水-力耦合特性——基于ATLAS Ⅲ现场加热试验

比利时放射性核废料地质备选场址Boom clay是一种典型的横观各向同性材料,在Drucker-Prager帽盖模型的基础上,构建了适用于Boom clay的横观各向同性特点的热-水-力耦合弹塑性本构模型,该模型可反映温度对其强度、弹性模量、渗透性等的影响,并在ABAQUS中进行了二次开发。为验证所建立模型的合理性,结合比利时HADES地下实验室ATLAS Ⅲ现场加热试验结果,应用所提出的模型对加热过程中围岩的温度和孔隙水压力的变化规律进行了数值仿真分析。结果表明:所建立的模型能够正确地描述现场加热试验过程中围岩温度场和孔压场所呈现出的各向异性特征,主要表现为热源水平面内测点的孔压在加热功率升高时先略为下降后才升高,在加热功率下降时先略为升高后才下降,而竖直面内测点的孔压在加热功率升高时立即升高,在加热功率下降时立即下降。研究成果表明,考虑各向异性的THM耦合分析能更好地反映加热过程中泥岩温度场和孔压场的实际分布情况,研究结果对类似工程或现场试验的设计、安全运行提供重要的决策依据。