TY - CONF A1 - Auersch, Lutz T1 - Modes and waves of coupled roof or floor structures in historical and modern buildings N2 - Long wooden floor beams above a ball room in an old historical palace have been analysed experimentally. The eleven beams are weakly coupled by three layers of floor boards. It has been investigated if the state (the stiffness) of the wooden beams can be determined by vibration measurements of global or preferably local modes. Hammer, heel-drop and ambient excitations have been used. The vibration modes of the structure show dominating local deformations if an impact excitation is applied. This is understood as the positive superposition of several modes which yield the maximum at the excitation point but a cancellation at more distant points. Natural modes have been estimated from these vibration modes by standard and special methods which were necessary for the high damping of the wooden floor. It has been found that all floor beams contribute to each natural mode even for a weak coupling of the beams. In addition to the modal discussion, the impact tests have also been analysed for the wave propagation and amplitude attenuation with distance. The coupling of floor beams has been studied theoretically by an analytic multiple-beam model where the coupling by translational or rotational springs and by a common support motion has been assumed. T2 - 23. International Congress on Sound and Vibration CY - Athen, Greek DA - 10.07.2016 KW - wave analysis KW - floor vibration KW - modal analysis PY - 2016 AN - OPUS4-37091 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - The dynamic behavior of railway tracks with under sleeper pads, finite-element boundary-element model calculations, laboratory tests and field measurements N2 - Results from the calculation of the tracks have been presented. The compliances for the different under sleeper pads have been intensely discussed by the experts. Laboratory tests and field tests have been shortly presented to demonstrate the comprehensive approach of the BAM. N2 - Es werden die Arbeiten der BAM zu schweren Schwellen und weichen Schwellensohlen vorgestellt. Es wurden Berechnungen zum Schwingungsverhalten und zur Erschütterungsminderung durchgeführt. Laborversuche dienten dazu, die elstischen Eigenschaften der Schwellensohlen und die Dauerhaftigkeit der schweren Schwellen zu ermitteln. In Feldversuchen wurde die Minderungswirkung mit Schwingeranregung und mit Zuganregung ermittelt. T2 - Treffen "Schwellen und Schwellensohlen" CY - Berlin, Germany DA - 25.02.2016 KW - sleeper pads KW - railway track KW - ground vibration KW - mitigation PY - 2016 AN - OPUS4-37103 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz A1 - Said, Samir A1 - Schmid, Wolfgang A1 - Wuttke, Wilfried T1 - Experimental and theoretical building and foundation behaviour T2 - EVACES'09 - Experimental vibration analysis for civil engineering structures CY - Wroclav, Poland DA - 2009-10-14 PY - 2009 SN - 978-83-7125-184-9 N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings SP - 133 EP - 142 AN - OPUS4-31259 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - The use and validation of measured, theoretical, and approximate point-load solutions for the prediction of train-induced vibration in homogeneous and inhomogeneous soils N2 - The layered soil is calculated in the frequency wavenumber domain and the solutions for fixed or moving point or track loads follow as wavenumber integrals. The resulting point load solutions can be approximated by simple formula. Measurements yield the specific soil parameters for the theoretical or approximate solutions, but they can also directly provide the point-load solution (the transfer function of that site). A prediction method for the train-induced ground vibration has been developed, based on one of these site-specific transfer functions. The ground vibrations strongly depend on the regular and irregular inhomogeneity of the soil. The regular layering of the soil yields a cut-on and a resonance phenomenon, while the irregular inhomogeneity seems to be important for high-speed trains. The attenuations with the distance of the ground vibration, due to point-like excitations such as vibrator, hammer, or train-track excitations, were investigated and compared. All theoretical results were compared with measurements at conventional and high-speed railway lines, validating the approximate prediction method. PY - 2014 SN - 1027-5851 VL - 19 IS - 1 SP - 52 EP - 64 CY - St. Petersburg, Russia AN - OPUS4-30494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Building response due to ground vibration - simple prediction model based on experience with detailed models and measurements N2 - Construction work, such as pile driving and soil compaction, or road and railway traffic excite nearby buildings, and the perceptible or audible vibration can be a nuisance for nearby inhabitants. A simplified building model has been created for these situations, which includes the effects of soil-structure interaction, the low-frequency amplification along the height of the building as well as the high-frequency reduction and the floor resonances. The model consists of one wall for all supporting structures (walls and columns) and one floor for each storey. The effect of different floor resonance frequencies is included in a stochastic procedure. The soil is modelled by a spring and a viscous damper, and the free-field amplitudes of the soil are applied under this soil element. The model can be calculated by transfer matrices or in a continuous wave-type version where an analytical solution can be evaluated numerically. The building response in the high-frequency (acoustic) region is calculated as mean values over wider frequency bands. The approach to an infinite building model can be found for these high frequencies and the corresponding soil-structure transfer can be described by the ratio of impedances at foundation level. The rules for choosing the parameters to obtain realistic results are derived from complex calculations for example, for the stiffness and damping of building foundations and many measurements as for the damping of floor resonances. The influences on the floor resonance from the soil (damping) and the supporting structure (detuning) are important. Some more effects will be discussed by the simplified and detailed models and by measurements to establish a good understanding of ground-induced building vibrations. PY - 2010 SN - 1027-5851 VL - 15 IS - 3 SP - 101 EP - 112 CY - St. Petersburg, Russia AN - OPUS4-22014 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Two- and three-dimensional methods for the assessment of ballast mats, ballast plates and other isolators of railway vibration PY - 2006 SN - 1027-5851 VL - 11 IS - 4 SP - 167 EP - 176 CY - St. Petersburg, Russia AN - OPUS4-18953 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Vehicle dynamics and dynamic excitation forces of railway induced ground vibration T2 - 21th International symposium on dynamics of vehicles on roads and tracks CY - Stockholm, Sweden DA - 2009-08-17 PY - 2009 SP - 1 EP - 12 CY - Stockholm, Sweden AN - OPUS4-21088 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz A1 - Said, Samir T1 - Vibration measurements for the control of damaged and repaired railway tracks N2 - The damage detection and repair control have become important tasks for ballast and slab tracks. Measurements which compare the damaged and the repaired status of the same track section at different times, or which compare a damaged and an intact track section at the same time, have been successfully performed at some sites in Germany with slab tracks and ballast tracks and compared with the theoretical behaviour of intact and damaged tracks. The loss of contact between the sleeper and the plate, between the plate and the base layer, and some problems with soft or weakened soil have been analysed. The observed results, changes in the time histories of displacements and velocities due to train passages and in the transfer functions (compliances) due to hammer impacts, are encouraging that these measurements can be used to detect track damage. In addition, calculations with the combined finite-element boundary-element method have been used to confirm the conclusions about intact or damaged railway tracks. T2 - 7th International Symposium on Environmental Vibration and Transportation Geodynmaics CY - Hangzhou, China DA - 28.10.2016 KW - Railway track KW - Slab track KW - Ballast track KW - Track-soil interaction KW - Field tests KW - Track damage monitoring KW - Finite element method KW - Boundary element method PY - 2016 SP - 3 EP - 19 AN - OPUS4-38261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Predicting, measuring and explaining the consequences of high-speed railway traffic in respect to the track, underground and environment N2 - Some results of our measurements of the Intercity experimental are presented together with simulated results and their interpretation. Three frequeny ranges could be measured and calculated: low frequencies which decrease very rapidly with distance (the quasi-static part), high frequencies (mainly due to the sleeper passage), and a mid-frequency which has the weakest attenuation with distance and is therefore dominant at the far field. Mono-frequent excitations get a wide frequency band due to the Doppler effect of the moving high-speed train. T2 - Seminar Fahrzeug-Fahrweg-Dynamik, TU Berlin - TH Warschau - BAM CY - Berlin, Germany DA - 25.02.1988 KW - High-speed trains KW - Doppler effect KW - Frequency-specific attenuation PY - 1986 AN - OPUS4-38080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz A1 - Said, Samir T1 - Methods and phenomena of single and coupled floor vibrations - Measurements in apartment and office buildings N2 - A survey of the phenomena and methods for floor vibrations is presented. Experimental results of floor vibrations are shown for many floors in six different buildings. The signals have been evaluated for waves and modes by simple procedures. General rules have been established between the material and the area of a specific floor, and its local eigenfrequency. The damping values of the floor vibrations have been found between D = 1 and 10 % where somewhat higher values have been measured for wooden floors, and a weak correlation with the eigenfrequency has been established. The velocities of bending waves propagating in a storey and the attenuation with distance in the building have been analysed. A considerable transfer of vibration from one room to far away parts of the building has been found in the studied buildings with concrete and wooden floors. An example building has been analysed for modes of coupled floor bays. The strong coupling of similar neighbouring floor bays would yield a wide band of global resonance frequencies. The measured wooden floor exhibits a weak coupling of the neighbouring floor bays and a narrower band of eigenfrequencies. A special method has been tested with the impulse measurements to estimate the coupled eigenmodes in presence of the high damping. From the ambient measurement, a low-frequency vibration mode has been detected which includes the vibration of the whole building and the soil. The coupling of floors to other floors and the whole building is an important phenomenon of structural dynamics which should be observed for the prediction of vibration due to internal and external sources. PY - 2015 SN - 1351-010X VL - 22 IS - 2 SP - 81 EP - 108 PB - Multi-Science Publ. Co. CY - Brentwood AN - OPUS4-34839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -