Helmut Rubin

Helmut Rubin

Helmut Rubin (born December 20, 1939 in Schwenningen ) is a German civil engineer and Austrian university professor

Life

Rubin grew up as the son of the chief surveyor Alfred Rubin and his wife Gertrud Rubin, nee. Dorner in Villingen in Baden. There he attended elementary school from September 1945 to July 1950 and then grammar school until March 1959. He often helped his father as a surveyor's assistant. After graduating from high school in Villingen, now in Baden-Württemberg, Helmut Rubin studied civil engineering at the TH Karlsruhe from November 1959 to July 1966 . His academic teachers included a. the statics professor Bernhard Fritz (1907–1980) and the influential steel construction professor Otto Steinhardt (1909–2000). In June 1967 the Faculty of Civil Engineering and Surveying honored him with the Tulla Medal, which is awarded every two years for the best diploma. The mechanics professor Horst Leipholz (1919–1988) advised him against his plan to continue studying mathematics and instead recommended the three-semester postgraduate course in applied mathematics and mechanics at the Faculty of Civil Engineering and Surveying, whose spirit was Rector Leipholz. Rubin was funded by the German National Academic Foundation and graduated with an exam in August 1970.

In September 1970 Steinhardt brought the talented Rubin to his chair for steel and light metal construction, which is closely associated with the research institute for steel, wood and stones. In January 1972 he was awarded a Dr.-Ing. Degree from the TH Karlsruhe with a dissertation on high-rise structures. PhD. In July 1972 Steinhardt arranged for him to work in industry for three months at Rheinstahl Union Brückenbau AG in Dortmund , which was then headed by Paul Boué (1920-2016). In the bridge office in Dortmund, Rubin took part in the extensive static calculations for the Hamburg Köhlbrand bridge . In October 1972 Rubin returned to the research institute as Steinhardt's research assistant. Finally he was won by the new statics professor Udo Vogel (1933–2015) for his institute for structural engineering and measurement technology at the TH Karlsruhe. Rubin worked there as chief engineer until September 1980. In January 1976, the TH Karlsruhe granted him the license to teach structural engineering. Rubin's habilitation thesis is entitled The load-bearing behavior of longitudinally stiffened, pre-deformed rectangular plates under axial load according to the non-linear buckling theory (taking into account the orthotropic structure and elastic support on the longitudinal edge) . It was based on extensive series of tests at the research institute and contained numerous diagrams which supported the design practice.

Rubin contributed his scientific findings to numerous specialist committees early on: Membership in Commission 8 (Stability, Task group 3: Plate buckling) and Commission 5 (plasticity) of the European Convention for Constructional Steelwork (ECCS), participation in the DASt subcommittee “Stability "(" Rods "working group), in 1978 he becomes chairman of the editorial committee DIN 4114 new (stability cases in steel construction) and finally a member of the standards committee DIN 18800 part 2 (stability cases, buckling of rods and frameworks).

In October 1980 Rubin accepted the call of the Vienna University of Technology as professor at the Institute for Structural Analysis. Since his retirement in 2009 Rubin has been teaching the elective Special Problems of the Second Order of Elasticity Theory in the winter semester .

In the first decade and a half of his creative period in Vienna, Rubin's scientific work continued to take shape: step by step he worked out the mathematical foundations of the planar rod theory . These fundamentals are that Rubin systematically dealt with the solution of linear ordinary differential equations of any order with non-constant coefficients resulting in converging series formulas. The distinction between tensile and compression loaded members according to the first and second order theory is thus obsolete. This becomes clear, for example, in the analogy of the formula apparatus between the tension rod according to the second order theory and the warping torsion in closed cross-sections. If the transverse force deformation for beams can be neglected with open cross-sections, this is no longer possible with closed cross-sections. In the plane bar theory in Rubin's mathematical version, the transverse force deformation is always "taken along". If, for example, multi-part bars are investigated according to the second order theory, the influence of the shear force deformations in lattice bars must not be neglected; in frame bars they are even predominant compared to moment deformations. Nevertheless, the formulas of the above fail. Analogy serves its purpose here, since numerical instabilities result from the difference between large numbers. A fresh start was necessary, and Rubin took this radical step. Since arching moments only occur and quickly decay if there is a hindrance to arching, he developed new formulas for a value and derived a single decay function - with this Rubin succeeded in creating a uniform representation of the planar theory of bars on a mathematical basis.

Since 1996, Helmut Rubin has presented his prize assignment in the November issue of Stahlbau magazine , the solution of which he publishes together with the names of the successful senders in the following March issue. He published a complete documentation from 1996 to 2018 with his son Daniel Rubin,

Fonts

• Rubin, H .: Interaction relationships between bending moment, shear force and normal force for single-symmetrical I and box cross-sections when bending around the strong and for double-symmetrical I-cross-sections when bending around the weak axis. In: Stahlbau 47 (1978), pp. 76-85.
• Rubin, H .: Interaction relationships for double symmetrical I and box cross-sections with biaxial bending and normal force. In: Stahlbau 47 (1978), pp. 145–151 u. Pp. 174-181.
• Rubin, H .: The rotation angle method for the calculation of rigid frameworks according to elasticity or plastic hinge theory of the 1st and 2nd order, taking into account pre-deformations. In: Bauingenieur 55 (1980), pp. 81-92.
• Rubin, H .: Structural analysis of flat frameworks . In: Stahlbau-Handbuch, Volume 1, Chapter 3, pp. 67-206, Cologne: Stahlbau-Verlags-GmbH 1982 (together with Udo Vogel).
• Rubin, H .: Rod systems curved in plan, improved, systematic formulation for the reduction process . In: Bautechnik 64 (1987), pp. 273-282.
• Rubin, H .: A uniform formulation of the planar rod problem taking into account M and Q deformations, first and second order theory, elastic bedding including rotational bedding as well as harmonic vibrations. In: Bauingenieur 63 (1988), pp. 195-204.
• Rubin, H .: A simple, general solution concept for linear differential equations of any order with constant coefficients and with an analytical perturbation function. In: Journal for Applied Mathematics and Mechanics (ZAMM) 68 (1988), pp. 433-443.
• Rubin, H .: A uniform, closed concept for the calculation of members with continuously changing cross-sections according to the first and second order theory. In: Bauingenieur 66 (1991), pp. 465–477.
• Rubin, H .: Structural engineering of flat frameworks, Sections 3.1 to 3.4. In: Stahlbau-Handbuch, Volume 1, Cologne: Stahlbau-Verlags-GmbH 1993.
• Rubin, H .: Solution of linear differential equations of any order with polynomial coefficients and application to a structural problem. In: Journal for Applied Mathematics and Mechanics (ZAMM) 76 (1996), pp. 105–117.
• Rubin, H .: Analytical calculation of bars and frameworks with constantly changing system sizes according to the first and second order theory. In: Bautechnik 76 (1999), pp. 316–327.
• Rubin, H .: Structural Analysis - First and Second Order Theory. 4th edition, Düsseldorf: Werner-Verlag , 2002 (together with K.-J. Schneider ).
• Rubin, H .: Determining the cutting and displacement sizes of circular arcs. In: Bauingenieur 79 (2004), pp. 176-184.
• Rubin, H .: Simplified calculation of the warping torsion of bars with thin-walled hollow cross-sections. In: Bauingenieur 81 (2006), pp. 538-544.
• Rubin, H .: Calculation of curved bars with circular hollow profile taking into account the cross-sectional deformation. In: Bautechnik 84 (2007), pp. 486–495.
• Rubin, H .: On the tautochrony of a rolling ball on the cycloid orbit. In: Stahlbau 86 (2017), pp. 852–855.
• Chapter Structural Analysis . In: Schneider building tables for engineers since 1992 in 10th to 23rd edition, now Bundesanzeiger Verlag GmbH Cologne.

literature

• Karl-Eugen Kurrer : Analytical thinking and playful structural engineering: 20 years of Christmas prize-giving in steel construction. In: Stahlbau, 85 (2016), no. 4, p. 241.
• Karl-Eugen Kurrer: Helmut Rubin 80 years. In: Stahlbau, 88 (2019), no. 12, pp. 1204–1205.

proof

1. ↑ Tulla Medal. KIT Faculty for Civil Engineering, Geo- and Environmental Sciences, accessed on January 1, 2020 . 
2. ↑ Rubin, H .: For the calculation of composite high-rise structures as discontinuous systems. Karlsruhe, Univ. Diss. 1972.
3. ↑ Rubin, H .: The load-bearing behavior of longitudinally stiffened, pre-deformed rectangular plates under axial load according to the non-linear buckling theory (taking into account the orthotropic structure and elastic support on the longitudinal edge). Karlsruhe, Univ. Habilitation thesis 1976.
4. ^ Rubin, H .; Rubin, D .: 22 years of the Christmas award . BoD - Books on Demand, Norderstedt 2018 (together with Daniel Rubin)
5. ↑ Anette Schober-Knitz: Daniel Rubin appointed professor for steel construction. Biberach University of Applied Sciences, February 3, 2015, accessed on January 1, 2020 .