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Presents a modular method for obtaining either a quick or a precise calculation for three‐dimensional structure assemblies with local non‐linearities, such as unilateral contact with friction, or technological components, such as prestressed bolt joints. An iterative method, including a domain‐decomposition technique, is proposed to solve such quasi‐static problems in small perturbations. Two types of entities are introduced: sub‐structures and interfaces. A local and a global stage are successively carried out by an iterative algorithm until convergence. The linear problem in the global stage is solved by a FEM (3D case) or by another approach using Trefftz functions (2D axisymmetrical case). Applications developed with AÉROSPATIALE‐Les Mureaux are presented and concern the study of structure joints with different types of flanges.

Two different methods to obtain crack propagation curves are considered in this work. In an analytical approach, the adhesion between the plates is considered perfect. In such case, the interface stiffness is not taken into account and the classic beam theory is used to study the behavior of the plates during the delamination. The second approach is numerical and the bonded interface is now considered elastic. The paper aims to discuss these issues.

The propagation curves are obtained with the aid of the finite element code CAST3M by taking the structural response for a given value of initial crack length at a time.

A good fit is achieved when analytical and numerical curves are compared. Finally, mechanical tests results are presented to validate the numerical method and to identify the critical energy release rate (G_c).

More than an easier method to obtain propagation curves, the numerical method presented in this paper is an important tool to selection of optimized test geometries.

This paper focuses on the design of a superconducting quadrupole prototype. This structure includes many frictional contact zones, and the loading conditions are complex (mechanical, thermal and magnetic). A dedicated computational strategy, based on both a decomposition of the structure and an iterative resolution scheme, has been applied to solve this problem. A simplified approach is used to take complex loading conditions into account. The initial set of results, which are presented herein, demonstrates the interest of this approach with respect to classical finite element methods. This study was conducted within the framework of a joint research contract between the CEA (DSM/DPANIA/STCM) and LMT‐Cachan.

Prismatic specimens were fabricated, consisting of two ceramic tiles bonded by an intermediate adhesive mortar layer. To simulate pre-existing defects, an acetate film was strategically inserted into one of the mortar-ceramic interfaces, creating controlled cracks of varying sizes. The specimens were subjected to low-amplitude cyclic loading, inducing simultaneous tensile and shear stresses within the system. The vibrational responses of the samples were recorded, and their frequency-domain amplitudes were analyzed.

Ceramic tile detachment remains a significant issue in contemporary construction, despite advancements in technology and updates to regulatory standards. The majority of these failures occur at the adhesive mortar-ceramic tile interface due to the combined effects of tensile and shear stresses. While this phenomenon is well-documented, experimental studies assessing the adhesion integrity of façade cladding systems are limited. This study aims to evaluate the adhesion performance of adhesive mortars using a non-destructive vibrational analysis technique.

The results enabled the characterization of the dynamic behavior of the specimens, identification of frequency regions corresponding to individual components, and formulation of diagnostic criteria for damage detection. Analysis of the resonance spectra also made it possible to identify a peak that can be related to the behavior of the mortar-substrate interface. Additionally, the elastic and dissipated energy metrics were calculated to quantify the system’s mechanical behavior. The study further investigated the impact of crack size, curing time and adhesive mortar type on the overall structural integrity.

This work aims to evaluate the adhesion performance of adhesive mortars using a non-destructive vibrational analysis technique. Resonance frequency measurements have also been used in research to analyze the propagation paths of cracks in metallic samples from aircraft engines. However, despite the widespread use of non-destructive techniques based on resonance frequencies for damage assessment, their application in the field of coating systems seems to be virtually unexplored. Therefore, this research attempts to address this gap by investigating the bond integrity of adhesive mortar joints, focusing on the analysis of the material’s resonance frequencies and their associated peak parameters.

This paper gives a bibliographical review of the finite element and boundary element parallel processing techniques from the theoretical and application points of view. Topics include: theory – domain decomposition/partitioning, load balancing, parallel solvers/algorithms, parallel mesh generation, adaptive methods, and visualization/graphics; applications – structural mechanics problems, dynamic problems, material/geometrical non‐linear problems, contact problems, fracture mechanics, field problems, coupled problems, sensitivity and optimization, and other problems; hardware and software environments – hardware environments, programming techniques, and software development and presentations. The bibliography at the end of this paper contains 850 references to papers, conference proceedings and theses/dissertations dealing with presented subjects that were published between 1996 and 2002.

Large structures (e.g. plane, bridge, etc.) often include several hundreds of assembly points. Structural computations often use over-simplistic approximations for these points; among others, they do not take into account the thermo-mechanical history due to the assembling process. Running computations with each assembly point modelled completely would require too much time to achieve a simulation. There is thus a need to create equivalent elements for assembly points in order to: take into account the mechanical state of the assembly point in the design stage – while reducing the computational time cost at the same time. This paper aims to discuss these issues.

This paper introduces an innovative strategy based on a coupling procedure between a finite element tool for modelling the assembly process in order to access to the mechanical state of the assembly point and an optimisation algorithm, in order to identify the equivalent element parameters.

The strategy has proven to be successful. A connector model easier to use and much faster than the complete model, has been obtained. Results obtained with this element are in good agreement with experimental tests in the case of multipoint assemblies and with the simulation results of the complete numerical model. Finally the connector model appears to be easier to use and much faster than the complete model, more difficult to model properly.

The main innovative aspects of this strategy lie in the fact that the creation of this equivalent element is based on a complete numerical approach. The thermo-mechanical history due to the assembly process is considered – the element parameters are identified thanks to an evolution strategy based on the coupling between a finite element model and a zero-order minimisation algorithm.

The purpose of this paper is to propose a virtual testing strategy in order to predict damping due to the joints which are present in the ARIANE 5 launcher.

Since engineering finite element codes do not give satisfactory results, either because they are too slow or because they cannot calculate dissipation accurately, a new computational tool is introduced based on the LArge Time INcrement (LATIN) method in its multiscale version.

The capabilities of the new strategy are illustrated on one of the joints of ARIANE 5. The damping predicted virtually is compared to experimental results, and the approach appears promising.

The tool which has been developed gives access to calculations which were previously unaffordable with standard computational codes, which may improve the design process of launchers. The code is transferred into ASTRIUM‐ST, where it is being used to build a database of dissipations in the joints of the ARIANE 5 launcher.

This paper presents an original approach for learning models, partially known, of particular interest when performing source identification or structural health monitoring. The proposed procedures employ some amount of knowledge on the system under scrutiny as well as a limited amount of data efficiently assimilated.

Two different formulations are explored. The first, based on the use of informed neural networks, leverages data collected at specific locations and times to determine the unknown source term of a parabolic partial differential equation. The second procedure, more challenging, involves learning the unknown model from a single measured field history, enabling the localization of a region where material properties differ.

Both procedures assume some kind of sparsity, either in the source distribution or in the region where physical properties differ. This paper proposed two different neural approaches able to learn models in order to perform efficient inverse analyses.

Two original methodologies are explored to identify hidden property that can be recovered with the right usage of data. Both methodologies are based on neural network architecture.