History of Hollow Structural Sections (HSS)
The outstanding properties of tubular shapes have been known to human for a long time. The initial inspirations might have come from nature, which offers a lot of examples of using hollow structural sections. As shown in Figure 1 nature makes use of these shapes to produce one of its most efficient and lightweight structures.
Figure 2- Using HSS in Persian civilization (Elam – 1500 BC)
Inspired by nature, engineers learned about the desirable properties of tubular shapes and tried to make use of them, even in their primitive structures. There are surprising and outstanding signs of using hollow structural sections as early as the period of the pre-historic Persian civilization. Figure 2 shows photos taken by FGA Company at Louvre Museum (2016, Paris, France) as a strong proof of pre-historic usage of steel hollow structural sections.
Starting from the early 19th century, HSS members have been used in a number of eye-catching and significant structures . However, their use was limited mostly due to the lack of efficient manufacturing techniques. Despite this, structural engineers constantly tried to take advantage of these profiles, since their mechanical properties are best suited for safe and lightweight structures. The 521-meter-long Firth of Forth Bridge in Scotland (1890) is one of the first known large structures that has utilized riveted HSS members in its primary load bearing system Figure 3.
In 1886 the skew roll piercing process (Schrägwalzverfahren) was introduced by Mannesmann brothers , as one of the first methods to produce “seamless welded circular hollow sections” . This was followed by Pilger process (Pilgerschrittverfahren), which made the manufacturing of “longer thinner walled seamless hollow sections” possible a few years later.
Major technological innovations in manufacturing HSS were introduced and employed during the 1930s . These included the production of welded circular hollow sections at the beginning of the 20th century. Since then, advanced manufacturing techniques such as continuous welding methods have been developed for HSS, leading to a significant growth of production in industrial countries.
Development of advanced welding processes grew faster after World War II . Besides, enhanced preparation of metal sheet ends for welding allowed for more continuous manufacturing processes, whereby the rolls of plates could be constantly fed into the forming machines. Furthermore, edge preparation machines facilitated the butt welding process, which added to the manufacturing quality of HSS.
By 1937, “Mero system” was developed by Mengeringhausen  (The name MERO is an abbreviation for Mengeringhausen Rohrbauweise, which translates to Mengeringhausen’s tubular structures) that facilitated industrial construction of structures involving HSS members and connections. In particular, this system consisted of standardized connecting elements that could be used to connect members on a variety of angles. This development continued to the extent that made HSS members the primary choice for space structures.
Much of the remaining production difficulties were solved during the 1950’s . However, connections between HSS members needed further improvement for widespread use. As a result, significant research was dedicated to connections involving HSS members, particularly rigid or semi-rigid types. In 1951, the first design instructions manual for HSS members was developed by Jamm . This was followed by numerous research works in japan [8, 9], USA [10-12] and Europe [4, 13-21].
The industrial manufacturing of rectangular hollow sections began
The industrial manufacturing of rectangular hollow sections began in 1952 . This major leap helped engineers to more easily design and create connections between HSS members, while keeping all the desirable properties of hollow sections.
The research on connections involving rectangular hollow sections gained added momentum in the 60’s in Europe. Many experimental and theoretical studies were conducted based on the static behavior of these connections, which were mostly sponsored by CIDECT . During the last 25 years, more advanced topics involving HSS members were introduced, including dynamic behavior, concrete-filled composite members, fire and corrosion resistance and their use in resistance to wind loads .
Usage of HSS members steadily continues to grow in structures and industry. The applications of HSS range from small structures to large space trusses. Examples include pedestrian bridges, airport terminals, shopping malls, buildings, and recreational complexes. HSS members have also been widely used in highway signs, guard rails, and power transmission towers over the recent years, as shown in Figure 4, Figure 5, Figure 6 and Figure 7..
In response to the ever-growing need for these structural members, the industry has now established a streamlined and high-quality manufacturing process for HSS. This involves manufacturing of HSS with fully automatic devices that receive the sheet metal from coils at the beginning of the line and pass it through in a process of cold working to form it into a round shape. Advanced welding methods such as electrical resistance welding (ERW) is now widely used to weld the longitudinal edges to minimize the resulting residual stresses and alterations in the properties of steel. The resulting closed sections then go through additional forming processes that finally lead to perfectly shaped circular, square or rectangular hollow sections.
- Backyard Design. 2016; Available from: http://zozeen.com/category/backyard-design/bamboo.
- Bamboo. 2016; Available from: http://www.momgoesgreen.com/bamboo-bamboo-bamboo.
- Bamboo Poles. 2016; Available from: http://bamboohabitat.com/bamboo-poles.
- J.Wardenier, Hollow Sections in Structural Applications. 2000, Netherlands: Delft University of Technology.
- Open Buildings. 2016; Available from: http://openbuildings.com/buildings/forth-bridge-profile-6308.
- A.G., M.W., Mannesmann Stahlbauhohlprofile (MSH) Anwendungsbeispiele,Technical Documentation. 1991, Düsseldorf, Germany.
- Jamm, W., Form strength of welded tubular connections and tubular structures under static loading. Vol. 3. 1951, Germany: Schweissen und Schneiden.
- Natarajan, M.a.T., A.A., Studies on tubular joints in Japan: Review of research reports. 1968: USA.
- Togo, T., Experimental study on mechanical behaviour of tubular joints. 1967, Osaka University: Japan.
- Natarajan, M.a.T., A.A., Studies on tubular joints in Japan: Review of research reports. 1969: USA.
- Bouwkamp, J.G., Concept on tubular joints design, in Proceedings of ASCE. 1964.
- Marshall, P.W.a.T., A.A., Basis for tubular design. ASCE preprint, 2008.
- Brodka, J., Stahlrohrkonstruktionen. 1988, Germany: Verlagsgesellschaft Rüdolf Müller, Köln-Braunsfeld.
- Dutta, D.a.W., K.G, Handbuch Hohlprofile in Stahlkonstruktionen. Verlag TÜV Rheinland GmbH. 1988, Köln, Germany: Verlag TÜV Rheinland GmbH.
- Dutta, D.a.W., K.G, Hohlprofilkonstruktionen. 1999, Berlin, Germany: Ernst & Sohn.
- Mang, F.a.B., Ö., Hohlprofilkonstruktionen, Stahlbau-Handbuch, Bd. . 1983, Köln, Germany: I, Stahlbau-Verlag.
- Puthli, R.S., Hohlprofilkonstruktionen aus Stahl nach DIN V ENV 1993 (EC3) und DIN 18 800 (11.90). 1998, Düsseldorf, Germany: Werner Verlag GmbH & Co. K.G.
- Rautaruukki, Design Handbook for Rautaruukki Structural Hollow Sections. 1998, Hämeenlinna, Finland.
- Stahlrohr, Handbuch: 9. Aufl. Vulkan. 1982, Essen, Germany.
- Wardenier, J., Hollow Section Joints. 1982, Delft, The Netherlands: Delft University Press.
- Wanke, J., Stahlrohrkonstruktionen. 1966, Vienna, Austria: Springer Verlag.
- CIDECT, Construction with hollow steel sections. 1984, Northants, U.K.: British Steel plc.