Exterior of the A. Godshaw Jewelry Store; Welwyn Garden City.

The store moved to larger quarters in the 1990s.

Exterior of the A. Godshaw Jewelry Store; Welwyn Garden City.

The store moved to larger quarters in the 1990s.

Numerical studies of gypsum plasterboard and MGO board lined LSF walls exposed to fire

Fire resistance of cold-formed light gauge steel frame (LSF) wall systems is enhanced by lining them with single or multiple layers of wall boards with varying thermal properties. These wall boards are gypsum plasterboards or Magnesium Oxide (MgO) boards produced by different manufacturers. Thermal properties of these boards appear to show considerable variations and this can lead to varying fire resistance levels (FRL) for their wall systems. Currently FRLs of wall systems are determined using full scale fire tests, but they are time consuming and expensive. Recent research studies on the fire performance of LSF wall systems have used finite element studies to overcome this problem, but they were developed based on 1-D and 2-D finite element platform capable of performing either heat transfer or structural analysis separately. Hence in this research a 3-D finite element model was developed first for LSF walls lined with gypsum plasterboard and cavity insulation materials. Accurate thermal properties of these boards are essential for finite element modelling, and thus they were measured at both ambient and elevated temperatures. This experimental study included specific heat, relative density and thermal conductivity of boards. The developed 3-D finite element model was then validated using the available fire tests results of LSF walls lined with gypsum plasterboard, and is being used to investigate the fire performance of different LSF wall configurations. The tested MgO board exhibited significant variations in their thermal properties in comparison to gypsum plasterboards with about 50% loss of its initial mass at about 500 ºC compared to 16% for gypsum plasterboards. Hence the FRL of MgO board lined LSF wall systems is likely to be significantly reduced. This paper presents the details of this research study on the fire performance of LSF wall systems lined with gypsum plasterboard and MgO board including the developed 3-D finite element models, thermal property tests and the results.

Portrait of Ernst Gottschalk with his wife Louise "Isa" nee Rosenthal; Welwyn Garden City, England.

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Wedding portrait of Freddy Gottschalk and Barbara Joan Doble with guests; Welwyn Garden City, England.

Portrait includes a number of family members who were able to get to England before the war and who chose to remain there.

Unidentified man, Elizabeth Krakauer nee Gottschalk and Hans Krakauer on board the ship Koenigstein traveling from Antwerp to New York City on their emigration voyage from Germany.

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Elisabet Eliasberg writing in her first American home after fleeing Hitler's Austria; 73 Payson Avenue, New York City Portraits Women

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Group portrait at the farewell banquet for Dr. William Antopol from the laboratory staff of Mount Sinai Hospital; Ken's Chop House, New York city Portraits Groups

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Albert Einstein with unidentified group; City College, New York Portraits Groups; Men

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Ed Sullivan being presented with a fancy layer cake from the Viennese Café Eclair in New York City for the 7th anniversary of the Ed Sullivan Show Entertainment

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Exterior of the A. Godshaw Jewelry Store; Welwyn Garden City.

The store moved to larger quarters in the 1990s.

Exterior of the A. Godshaw Jewelry Store; Welwyn Garden City.

The store moved to larger quarters in the 1990s.

Out-of-plane deformation and failure of masonry walls with various forms of reinforcement

Out-of-plane behaviour of mortared and mortarless masonry walls with various forms of reinforcement, including unreinforced masonry as a base case is examined using a layered shell element based explicit finite element modelling method. Wall systems containing internal reinforcement, external surface reinforcement and intermittently laced reinforced concrete members and unreinforced masonry panels are considered. Masonry is modelled as a layer with macroscopic orthotropic properties; external reinforcing render, grout and reinforcing bars are modelled as distinct layers of the shell element. Predictions from the layered shell model have been validated using several out-of-plane experimental datasets reported in the literature. The model is used to examine the effectiveness of two retrofitting schemes for an unreinforced masonry wall.