Publications de Alain Nussbaumer

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Connections between structural glass components represent one of the main critical aspects of glass engineering. In the last years, a novel typology of adhesive connections has emerged, known as laminated adhesive connections. Two adhesive materials for la ...

Accurate measurement-data interpretation leads to increased understanding of structural behavior and enhanced asset-management decision making. In this paper, four data-interpretation methodologies, residual minimization, traditional Bayesian model updatin ...

A study of non-anchored tanks found in Switzerland (Koller, 2003) revealed that the plastic rotation of the shell-to-bottom connection in four of the six tanks studied did not satisfy the 0.2 radians limit established by the Eurocode (Eurocode-8, 2005). The fact that tanks could undergo fracture in their shell-to-bottom connection prompted further investigation with funding from Carbura and OFEV. The investigation focused on determining the real capacity of the shell-to-bottom connection since the current l

Recents studies have shown that the use of improvement techniques on welds allows an increase in the level of admissible fatigue strength (even more than 100%). The aim of this study was to collect and validate literature data, create a data base containing the joint characteristics and fatigue results, make a statistical analysis of the data in order to quantify the effect of parameters influencing the fatigue strength and propose new S-N curves which are compared to those given in Eurocode 3. Four improve

Fatigue damage accumulation and failure of steel reinforcement bars (rebars) is a stochastic process. Scatter can be influenced by the sensitivity of the short crack growth to the microstructural features, especially near the fatigue limit. This work inves ...

Fatigue cracks tend to initiate on the rebar surface and therefore, the surface conditions may control their fatigue behaviour. This study investigates the influence of surface microstructure and roughness dispersion on the scatter and fatigue life of hot ...

The effectiveness of post-tensioning in enhancing the fracture resistance of glass beams depends on the level of compressive pre-stress introduced at the glass edge surface that will in service be exposed to tensile stresses induced by bending. Maximum pre ...

Unanchored steel tanks subjected to strong ground motion may experience rocking motion if the moment generated by the inertial mass of the content stored is greater than the resisting moment provided by the weight of the tank and its content. Rocking of the tank causes the shell-base welded connection to undergo cycles of rotation. The Eurocode provides a methodology for estimating the maximum rotation that this connection may experience. This methodology was applied to study six tanks located in Switzerlan

This paper provides a new advanced probabilistic approach for reliable estimation of the fatigue characteristic S-N curves of welded joints both for constant amplitude (CA) and variable amplitude (VA) loading conditions. The presented approach, which is re ...

When an unanchored tank is subjected to strong motion, the impulsive mass of the contained liquid generates a moment which if strong enough could cause partial uplifting of the base plate. As the tank undergoes uplifting, the shell-base welded connection is subjected to cycles of rotation which could lead to its failure. To address this issue, the Eurocode and the New Zealand’s recommendations limit the rotation amplitude that the shell-base connection of a tank may undergo to 0.2 radians. This limit is obt

This paper presents the findings from an international workshop that brought together various NGOs, rebuilding coordinators, private sector leaders, engineers, and academics to discuss methods and issues related to fast reconstruction in developing regions affected by natural disasters. Natural disasters in developing regions often destroy homes and, together with economic conditions, force people to live in temporary shelters such as tents. Experience shows that rebuilding is often a long process because o

The loss of material ductility in the presence of very high amplitude cyclic straining is an observed phenomenon in many extreme conditions like earthquake loadings. This phenomenon is called ultra-low cycle fatigue (ULCF) and failure is often achieved in a few number of cycles – around 5 to 10. Design to ULCF often involves the use of finite element (FE) models to assess the plastic strain history at critical points in a component. In the case of a welded joint, a number of factors contribute to its ultima

A critical aspect in the design of tubular bridges is the fatigue performance of the structural joints. The estimation of a fatigue crack life using the linear elastic fracture mechanics (LEFM) theory involves the calculation of stress intensity factors (S ...

Earthquakes around the world have affected many unanchored tanks used for storage of gasoline. When these unanchored tanks are subjected to strong motion, the moment generated at the base, by the mass of liquid contained in the tank, will cause partial upl ...

The majority of fatigue strengthening studies focus on reducing propagation rates of existing cracks, ignoring the crack initiation stage. Many existing metallic bridge members however do not contain existing cracks, but rather are nearing their design fat ...

This paper presents a study on post-tensioned glass beams in a statically indeterminate system. In order to increase the safety of structural glass beams, ductile reinforcement can be added to glass beam sections providing secondary load carrying mechanism ...

Extreme events often subject regions of structural steel components to large inelastic strains. In conditions such as earthquakes, exceptional winds gusts or tides the loading scenario is cyclical, variable amplitude and frequently multiaxial in nature, an ...

Ultra low cycle fatigue (ULCF) is a phenomenon that can be summarily defined as the deterioration of material properties under high amplitude cyclic loading, under which failure is reached typically within ten to twenty cycles. This phenomenon is observed in extreme loading scenarios such as earthquakes or exceptional winds where large cyclic strains are expected. Particularly sensitive are structural components that are designed to absorb the loading’s energy through plastic dissipation, like moment or she

In many design codes for roadway bridges, fatigue design involves passing a load model over an influence line for a critical location on the bridge and then determining the resulting nominal stress range. For fatigue design in the finite-life domain, this ...

Gasoline and other oil byproducts are commonly stored in steel tanks that rest on ground without any anchorage. Under strong motion, the impulsive mass of the contained liquid generates a moment about the base of the tank capable of causing partial uplift ...

Alain Nussbaumer

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Laminated connections for structural glass applications under shear loading at different temperatures and strain rates

Comparing methodologies for structural identification and fatigue life prediction of a highway bridge

Seismic Behavior of Shell-to-Base Connections in Large Storage Tanks

Analysis of results on improved welded joints

Microstructural influence on the scatter in the fatigue life of steel reinforcement bars

Fatigue behaviour prediction of steel reinforcement bars using an adapted Navarro and De Los Rios model

Post-tensioning of glass beams: Analytical determination of the allowable pre-load

Seismic Behavior of Shell-Base Connections in Large Storage Tanks

Estimation of fatigue S-N curves of welded joints using advanced probabilistic approach

Experimental Study on the Seismic Behavior of Shell-Base Connections in Large Storage Tanks

On fast transition between shelters and housing after natural disasters in developing regions

The influence of weld geometry on plastic strain history in cyclic loading – a parametric study

Advanced Numerical Modeling of Cracked Tubular K Joints: BEM and FEM Comparison

Experimental Determination of the Capacity of Wall-to-Base Connections in Storage Tanks

Determination of minimum CFRP pre-stress levels for fatigue crack prevention in retrofitted metallic beams

Experimental investigation of multi-span post-tensioned glass beams

Multiaxial ultra low cycle fatigue in welded high strength steel structural components

Ultra low cycle fatigue of welded steel joints under multiaxial loading

Simultaneous Vehicle Crossing Effects on Fatigue Damage Equivalence Factors for North American Roadway Bridges

Cyclic demand at the shell-bottom connection of unanchored steel tanks