TY - JOUR A1 - Helmerich, Rosemarie A1 - Zunkel, Astrid T1 - Partial collapse of the Berlin Congress Hall on May 21st, 1980 JF - Engineering failure analysis N2 - The Berlin Congress Hall was a gift of the United States of America to Germany for the Berlin World Exhibition in 1957. The elegantly double-curved roof was made from an advanced prestressed concrete construction. The construction followed the design by the American architect Hugh Stubbins with special structural modifications to comply with German construction rules. No early indications for failure initiation were detected before a sudden partial collapse. On May 21st, 1980, the Southern external roof overhang collapsed. In December 1980, Jörg Schlaich and his co-authors published a summarizing expert opinion about structural causes of failure. The present paper mainly introduces results of cause analysis made at the Federal Institute for Materials Research and Testing (BAM), mandated by the Public Prosecutor at the Berlin District Court to specify the causes of the sudden failure. This paper refers to BAM-publications about analyses that were performed under this mandate and published – most of them in German language – within the first years after failure. The expert's opinions comprise structural considerations materials investigations, metallographic analyses and corrosion. Nowadays experts have learnt from the failure and built a slightly modified roof in the original shape at the 750th birthday of the city of Berlin and re-opened the former Berlin Congress Hall to the public on May 9th, 1987. The Hall is now serving as the House of the Cultures of the World, following the initial intention of the hall. KW - Partial collapse KW - Berlin Congress Hall KW - Analysis KW - Stress corrosion cracking KW - Reconstruction PY - 2014 DO - https://doi.org/10.1016/j.engfailanal.2013.11.013 SN - 1350-6307 SN - 1873-1961 VL - 43 IS - Special Issue 'A Tribute to Prof. A. Martens' SP - 107 EP - 119 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-30863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zunkel, Astrid A1 - Tiebe, Carlo A1 - Schlischka, Jörg T1 - “Stolt Rotterdam” - The sinking of an acid freighter JF - Engineering failure analysis N2 - The Stolt Rotterdam tanker ship, filled with nitric acid, was unloading at the Krefeld-Uerdingen terminal on the Rhine River in November 2001. Nitric acid ran out of the stainless steel tanks into the ship's hull and damaged the structural steel. The ship then caught fire and sank at the terminal. Large quantities of nitrogen oxides were emitted, which drifted towards a residential area. Additionally, a mixture of acid and water was introduced into the Rhine River. The area became hazardous to people and the natural environment; however, the imminent danger for the residents and the environment was reduced because of the protective measures against pollution and the good teamwork between local authorities, fire brigades and the Bayer AG company. The acid was drained off of the ship using a controlled discharge of the acid into the river. Through the use of this measure, the ship was salvaged, limiting the pollution to the area and removing the health hazards to the people and the environment. After the ship was salvaged, the river police, along with assistance from the BAM Federal Institute for Materials Research and Testing, impounded the ship and selected corroded parts for further examination. Some of these components have been examined in detail by the BAM. These material investigations contributed to the elucidation of the origin of the leak in the floor panel. The cause of damage was deemed to be a result of a construction flaw at the enamelled valve on the load and discharge pipes. The results from the comparative corrosion testing using the original structural steel and 60% acid revealed that the valves began to leak at least 8 h prior to the incident at the terminal. KW - Freighter KW - Nitric acid KW - Corrosion KW - Valve KW - Flat gasket PY - 2014 DO - https://doi.org/10.1016/j.engfailanal.2014.03.002 SN - 1350-6307 SN - 1873-1961 VL - 43 IS - Special Issue 'A Tribute to Prof. A. Martens' SP - 221 EP - 231 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-31596 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klein, Ulrich A1 - Zunkel, Astrid A1 - Eberle, Arno T1 - Breakdown of heat exchangers due to erosion corrosion and fretting caused by inappropriate operating conditions JF - Engineering failure analysis N2 - Damage analyses on two heat exchanger units showed that in both cases inappropriate flow conditions of media caused very different failure mechanisms that resulted in irreparable damage. The first incident was the breakdown of an unalloyed steel condenser, which operated in a coal-fired power plant. A considerably high number of tubes successively leaked. Metallography identified lines of segregation in the microstructure of the tube walls, thus, giving evidence that both uniform corrosion and erosion corrosion caused by low-pressure wet steam were the root cause. The second incident was the breakdown of a recuperator made from chromium–nickel steel due to mechanical damage to tubes and baffle. This unit operated as part of a pilot plant to regain heat from the drying process of sewage sludge. It turned out that soiled vapour caused clogging of the cross-sectional area and therefore accelerating the flow velocity of the vapour. This inappropriate operating condition caused the tubes to oscillate so severely that they even banged together. Abrasive wear especially at the intersection through the holes of the baffle damaged the tubes and the whole unit irreparably. KW - Corrosion KW - Condenser KW - Recuperator KW - Soiled media KW - Leakage of tubes PY - 2014 DO - https://doi.org/10.1016/j.engfailanal.2014.03.019 SN - 1350-6307 SN - 1873-1961 VL - 43 IS - Special Issue 'A Tribute to Prof. A. Martens' SP - 271 EP - 280 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-31597 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Helmerich, Rosemarie A1 - Häcker, Ralf A1 - Zunkel, Astrid ED - Biliszczuk, Jan ED - Bien, Jan T1 - Cast iron arch bridges - part of the world heritage T2 - Arch Bridges in Culture N2 - Cast iron arch bridges were built in the late 18th and early 19th century across Europe. After the famous Iron Bridge in the Ironbridge Gorge in Coalbrookdale in England, being now part of the UNESCO world heritage, many cast iron bridges followed and substituted timber bridges. A series of cast iron bridges has been built in central Europe, in Laasan, Breslau, (now Wrocław), in Berlin, Potsdam, Bad Muskau and Schwerin. The paper gives an overview about the current state of some remaining cast iron arch bridges, typical damage cases, material properties and rehabilitation. Most of the old cast iron arch bridges serve as pedestrian bridges. Some of these bridges have been strengthened to increase the traffic load. Different rehabilitation measures as substitution of parts of the bridges and strengthening using Carbon Reinforced Polymers (CFRP) are discussed. T2 - Arch 2016 CY - Wroclaw, Poland DA - 05.10.2016 KW - Arch bridges KW - Cast iron KW - Materials parameters KW - Rehabilitytion PY - 2016 SN - 978-83-7125-265-5 SP - 194 EP - 197 PB - Dolnośląskie wydawnictwo edukacyjne CY - Wroclaw, Poland AN - OPUS4-38476 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -