厚/薄梁和板的通用动力有限单元

本文以位移模式,从研究通用于厚/薄梁的动力有限单元入手,得到了通于薄板和中厚板的九个自由度三角形和十二个自由度矩形动力有限单元。     

粘-弹层合板的阻尼振动和横向应力

应用混合分层理论在板的厚度方向取二次插值函数描述每个数值层内位移沿厚度方向的变化规律,采用三次和四次插值函数描述横向应力沿厚度方向的变化,推导出粘-弹层合板的动力学方程,并得出简支粘-弹层合板自由阻尼振动的解.数值结果不仅与三维结果吻合较好,且能够计算合理协调的横向应力.     

The Production and Deposition of the Guisborough Helmet

In September 1878 the British Museum received a donation of a folded metal plate which had been embossed and gilded. Restoration of the object revealed that the folded plate was in fact the outer casing of a Roman copper alloy cavalry sports type helmet which dates to the late second or third century AD. The story of what became known as the Guisborough helmet began 14 years earlier in what was then the North Riding of Yorkshire when workers employed by the Cleveland Railway Company discovered a ‘very curious plate of metal’ during road construction. It appears that the helmet was deliberately prepared for deposition and buried at a depth of c30 cm close to a stream. Examination by the authors suggests that this was a high value item that had been repaired many times. Experimental evidence suggests that the decoration alone required approximately 16 h to fashion.     

Armour in Henry V’s Great Wardrobe

Abstract

The unpublished accounts of two of King Henry V’s armourers, Martin Pull and John Hill, shed new light on the armour worn by the king and his circle during his campaigns to France which culminated in the great victory at the battle of Agincourt in 1415.     

Conserving a Late Eighteenth–Early Nineteenth Century Indian Helmet: A Technical Study

This paper describes the treatment of a distinctive late eighteenth/early nineteenth-century helmet from Gwalior in India known as a kolah khud or top. The fine mail aventail of the helmet, comprised of butted rings of iron or steel and brass, had fallen into a severe state of disrepair and was at risk of further deterioration without interventive conservation. The processes of replicating new mail rings and integrating these into the original structure as well as cleaning the helmet are discussed together with an analysis of the ethical implications of such actions.     

Thomas Firth and Sons – Steelmakers to the Arms Industries. Part 2: Heavy Armaments

Firth’s were the first of the Sheffield steel makers to enter the field armaments. Their involvement with Colt has been outlined in an article in the journal of the Colt Collectors Association in America and their activities as steelmakers to the small-arms industries has been covered in a previous issue of this Journal. This article gives a brief overview of their involvement as manufacturers in the field of heavy armaments, being the first to make all-steel guns and their evolving role in the use of steel for ordnance, culminating in the displacement of wrought iron by the adoption of steel for ordnance manufacture by the Royal Gun Factory in the 1880s. It also highlights their development of stainless steel in this context.     

Mass-Produced Pre-Han Chinese Bronze Crossbow Triggers: Unparalleled Manufacturing Technology in the Ancient World

Abstract

After an introduction to pre-Han and Han bronze crossbow triggers and bronze casting in China, these ancient mechanisms are examined from an engineering and manufacturing perspective. These triggers have been identified (Yates 2007) as the first mass-produced interchangeable military artefact. This examination shows that the sophisticated design of the mechanism clearly took manufacture into account and leads to the hypothesis that the key component of the mechanism, the nut, was specifically designed to be made by the stack moulding process identified by Barnard and Tamotsu 1975 as a technique ‘unparalleled in the ancient world’.     

弹性薄板的条形传递函数单元模型

应用改进的条形传递函数方法 ,建立了弹性薄板的二结线四自由度条形单元模型 ,用于分析系统的静力响应。用结线将矩形区域划分为条形单元 ,将边界结线离散 ,以内部结线和边界结点的位移和转角为未知量 ,采用三次插值 ,得到能够与有限元单元耦合求解的超级单元。利用广义函数给出了一种精确积分方法 ,可以得到有关矩阵的显式表达 ,得到提高了求解精度和效率。     

A German High Tournament Saddle in the Royal Armouries,Leeds

The Royal Armouries of Leeds preserves a rare example of an early fifteenth-century German tournament high saddle that is also one of the earliest complete western medieval saddles preserved. It bears witness to an extreme form of tournament which stood very far from the real practice of war: the Hohenzeuggestech. Impact marks of lances and swords, visible on the saddle, reveal the violence of the blows exchanged during these meetings, a violence often hard to observe in the contemporary but conventional representations of jousters and tourneyers. Thus, by the means of its excellent state of preservation, the Leeds high saddle sheds some light on the jousts and tourneys on high saddles, once so popular and plentiful in what remains of the civilian iconography of the late fourteenth- and the fifteenth-century Germanic world.     

The Archduke and the Bullet-Proof Vest: 19th-Century Innovation Versus 20th-Century Firepower

Abstract

To substantiate or otherwise the historical rumours that claim that the Archduke Franz Ferdinand failed to wear a piece of silk bullet-proof body armour on the day of his assassination, 28 June 1914, the likelihood of the Archduke possessing this invention is assessed and its composition and design is considered. The capabilities of such armours, the brainchild of priest-turned-inventor Casimir Zeglen, against the FN Browning Model 1910, in .380 ACP, the same model of self-loading pistol used to assassinate Franz Ferdinand, were tested.