https://popups.uliege.be/2684-6500 fr https://popups.uliege.be/2684-6500/index.php?id=347 Editor-in-chief Arnaud Deraemaeker & Gaëtan Kerschen Editorial Board The board of editors is updated yearly during the Editorial Board Meeting. Associate editors Arnaud Deraemaeker (ULB, Belgium) - Editor-in-Chief - Structural health monitoring, finite element modeling, mechatronics modeling Gaëtan Kerschen (ULiège, Belgium) - Editor-in-Chief - Nonlinear dynamics, system identification, vibration absorption Marta Berardengo (UniGe, Italy) - Passive vibration control, system identification, smart structures Matthew Brake (Rice University, USA) - Contact and impact mechanics, tribology, UQ Christophe Collette (ULiège, ULB, Belgium) - Active vibration control and damping Elizabeth Cross (University of Sheffield, UK) - Structural health monitoring Morvan Ouisse (UBFC, France) - Passive vibration control, vibroacoustics, smart structures Daniel Rixen (TUM, Germany) - Model reduction, domain decomposition, rotor dynamics, biodynamics, experimental techniques, hybrid simulation, robotics Olivier Thomas (ENSAM Lille, France) - Nonlinear dynamics, passive vibration control Paolo Tiso (ETH Zurich) - Model order reduction and substructuring of nonlinear structural and multiphysics systems Alessandra Vizzaccaro (Politecnico di Milano, Italy) - Computational nonlinear dynamics, reduced order modeling Keith Worden (University of Sheffield, UK) - Nonlinear dynamics Junior associate editors Pierre Margerit (ENSAM, France) - viscoelasticity, composites, additive manufacturing Shashank Pathak Fri, 25 Sep 2026 00:00:00 +0200 https://popups.uliege.be/2684-6500/index.php?id=347 https://popups.uliege.be/2684-6500/index.php?id=350 Previous studies have shown that one can create an efficient model for bolted structures by spidering the interface to a pair of nodes, and then connecting them with a nonlinear Iwan element. However, no method has been developed for predicting the parameters of the Iwan element from first principles; in all studies to date, experimental vibration measurements have been acquired and optimization has been used to solve for the Iwan parameters that best reproduce the measurements. This work investigates an alternative strategy that uses a local finite element model in which the bolt and surrounding area are modeled in detail with contact, Coulomb friction and the applied preload. A series of static loads are then applied to this local model and the resulting nonlinear force-displacement behavior is extracted and used to identify either a linear spring or an Iwan element that captures the predicted behavior. The identified springs and Iwan elements are then inserted into a reduced-order model of the structure, and the effective, amplitude-dependent natural frequency and damping of several modes of the structure can be computed, or dynamic transient analysis performed. This work evaluates the proposed modeling strategy using two-dimensional models of cantilever beams containing one and three bolts. In each case, the frequency and damping behavior of the reduced order models, whose Iwan elements were identified using the proposed procedure, are compared those of a truth model. The results show that, while each bolt in a structure can be loaded quite differently, the proposed procedure provides a reasonable approximation to the damping behavior of a joint, predicting the average nonlinear damping in the system within a factor of 1.5-3. Thu, 20 Aug 2026 00:00:00 +0200 https://popups.uliege.be/2684-6500/index.php?id=350 https://popups.uliege.be/2684-6500/index.php?id=300 Vibration testing of nonlinear structures presents various challenges that are not only related to the nonlinear structure itself but also to the exciter. As the exciter and the structure are coupled, the structure's nonlinear behaviour distorts the exciter force amplitude and frequency content, making the test results more difficult to compare with numerical predictions or even less accurate when isolating and identifying nonlinear normal modes (NNMs). This paper uses an adaptive feedforward cancellation (AFC) real-time control algorithm to track multi-harmonic force reference signals accurately. The controller estimates the disturbance generated by the structure and adjusts the exciter's input to compensate for it, recovering the desired force signal. The advantage of this approach is that it does not rely on the knowledge of the exciter and structure models. It only requires knowledge of the phase at the output of the exciter, which is straightforward to estimate experimentally from the force measurements. The effectiveness of the AFC for exciter force control is demonstrated numerically and experimentally on a cantilever beam structure excited by an electromagnetic shaker. The beam's free tip is attached to a spring mechanism, giving rise to geometric nonlinearities and mode interactions resulting in strong harmonic distortions in the excitation force. The method is further demonstrated on a compressor blade from Roll-Royce's aero-engine. Tue, 16 Jun 2026 00:00:00 +0200 https://popups.uliege.be/2684-6500/index.php?id=300 https://popups.uliege.be/2684-6500/index.php?id=345 What is the Journal of Structural Dynamics ? [video:jsd] Aims and scope The Journal of Structural Dynamics (JSD) invites original contributions, both theoretical and experimental, that advance innovation and understanding across the field of structural dynamics. We welcome manuscripts on a wide range of topics, including but not limited to : Active and passive vibration control Additive manufacturing Biomechanics Modal analysis Model reduction Model validation Next-generation materials including metamaterials Nonlinear dynamics Signal processing Structural health monitoring and damage detection System identification Uncertainty quantification Vibroacoustics Wave propagation JSD places no restrictions on the length of submissions. We accept various paper formats, such as regular papers, short notes, review papers, data or software papers. To promote open science, authors are encouraged to share experimental data and source code alongside their work. JSD publishes regular issues, typically one per year. The latest issue remains open and papers are published directly online, as soon as they are accepted. The JSD also publishes special issues. A guest editor, who does not have to be a member of the editorial board, is in charge of making the publicity for the special issue and organizing the review process. The review process follows the same standards and procedures as for the regular issues. The guest editor has the full support of one of the chief editors of the journal. Publi Wed, 06 May 2026 00:00:00 +0200 https://popups.uliege.be/2684-6500/index.php?id=345 https://popups.uliege.be/2684-6500/index.php?id=348 Manuscript preparation Manuscripts must be prepared using the provided LaTeX templates (package), formatted in the review style, and submitted as a PDF. Each submission must also include a Letter to the Editors (maximum 2 pages), which should : briefly outline the context and relevance of the research. highlight the novelty of the work compared to the state-of-the-art, including recent publications in the field. for review articles, explain why the review is timely, unique, and insightful. detail the added value of the methods or experiments presented, specifying their advantages over existing techniques and their potential applications. The Letter to the Editors must also be written using the provided LaTeX template and submitted as a PDF. Manuscripts and accompanying letters with poor English quality or numerous typographical errors will be rejected prior to peer review. Article submission Articles and Letters to the Editors should be submitted via email to Arnaud Deraemaeker at arnaud.deraemaeker@ulb.be. Prior to submission, authors are encouraged to consult with the associate editor specializing in their field before submission (see editorial board) in order to make sure that the paper aligns well with the journal's scope and expectations. Authors are encouraged to deposit all versions of their manuscript in repositories such as arXiv or HAL. Additionally, sharing scripts, data, and experimental results is highly encouraged. Authors can use platforms like Zenodo to create Wed, 06 May 2026 00:00:00 +0200 https://popups.uliege.be/2684-6500/index.php?id=348 https://popups.uliege.be/2684-6500/index.php?id=320 Modal analysis is the primary means of analyzing structural responses to external forcing, informing decision-making or further physical testing of the structure. Nevertheless, most commercially available solutions assume the test article behaves linearly with excitation amplitude. If significant amounts of nonlinear stiffness or damping are present in the structure, large errors in linear analysis may result which could lead to improper decisions that may be costly. Therefore, it is useful to develop experimental techniques or computational models which account for nonlinearity during modal analysis. This paper describes a method of generating frequency response functions at various excitation energy levels to generate a three-dimensional transfer function surface. The resulting transfer function surface is agnostic of drive-point location, allowing excitations at different drive points to be compared directly. This result holds only if the drive point is sufficiently far from node points. The Brake-Reuss beam is used as the experimental exemplar at various levels of impact testing. Best practices learned during experimentation are included. Mon, 09 Mar 2026 00:00:00 +0100 https://popups.uliege.be/2684-6500/index.php?id=320 https://popups.uliege.be/2684-6500/index.php?id=314 Substructuring is an important step in the analysis of complex built-up structures. It is the process by which individual components are mathematically assembled to build a model of a coupled system. In the frequency domain, admittance or FRF-based substructuring has become the preferred approach, especially when considering experimental components for which FRFs are easily obtained from test data. However, FRFs are not the only way to represent a component in the frequency domain. Often, particularly for layered systems, the so-called transfer matrix (TM) representation becomes more convenient; component coupling is achieved by simply multiplying together their respective TMs. In the present paper we develop a hybrid substructuring scheme that allows the coupling of FRF-based components using a TM representation of the interconnecting junction. Such an approach might be beneficial for structures with complex layered connections (well suited to TM-based coupling), and has the potential to provide additional insight into structural transmission through multiple interconnected elements. Thu, 08 Jan 2026 00:00:00 +0100 https://popups.uliege.be/2684-6500/index.php?id=314 https://popups.uliege.be/2684-6500/index.php?id=306 An interference fit is a common joining technique used to connect a shaft and a hub. In the presence of dynamic loads and vibrations, characteristic variables such as contact pressure and slippage are load and state-dependent quantities. Such effects have either not been investigated using previous simulation methods or have only been addressed in a simplified manner. The reason for this is the nonlinear contact between the shaft and the hub, which makes a Finite Element simulation with fine meshing, while taking all dynamic effects into account, very demanding and significantly increases the computational effort. This work also offers a new and alternative view of contact modes. This perspective is particularly advantageous for structures with initial stresses that occur in the presence of an interference fit. In this paper, so-called contact modes are applied to interference fits with some modifications. This closes the previously mentioned gap in the simulation landscape because it allows nonlinear, accurate, and fast numerical time integration of finely meshed Finite Element models with interference fits, without the need for simplifications regarding contact, friction, and dynamics due to vibrations and nonlinear rigid body motion. Local plasticity and temperature fields were not taken into consideration. Wed, 07 Jan 2026 00:00:00 +0100 https://popups.uliege.be/2684-6500/index.php?id=306 https://popups.uliege.be/2684-6500/index.php?id=285 Additive manufacturing has gained popularity for its ability to produce complicated geometries that distribute material optimally and allow several parts to be consolidated into one. Part consolidation often comes with a large reduction in damping, however, due to the elimination of frictional losses at interfaces between parts. This reduction of damping can be problematic in applications where resonant vibrations lead to early fatigue failure or undesirable noise emission. In recent years, a promising technique for increasing damping in parts made by laser powder bed fusion (LPBF) has been introduced, in which pockets of retained, unfused metal powder act as embedded dampers. This work presents an experimental study of the nonlinear behavior of several 316L stainless steel rectangular beams made by LPBF with embedded powder dampers. In addition to amplitude-dependent nonlinearity, a significant memory effect is observed, thought to be caused by powder settling and unsettling in response to external agitation. A procedure was developed to measure the full range of damping behavior by causing the system to transition between high-damping and low-damping states. This procedure is applied to six beams with varying pocket thicknesses, resulting in a rich dataset that provides insight into the factors that most influence the effective modal damping and natural frequency of these parts. As pocket thickness increases, the damping increases, together with the amount of nonlinearity and the variance in damping and natural frequency. This uncertainty can be reduced by controlling the amplitude range of interest, the powder state, the drive point, the impact force, and the hammer tip. The relative importance of each of these factors is quantified, and each factor is found to be significant in certain cases. Some of the parts are shown to exhibit significant modal interactions, as well as time-varying phenomena, for some modes. Additionally, a study which varied the operating temperature is presented, confirming that the behavior of trapped-powder dampers is largely temperature-independent. Implications of these findings for design and modeling are discussed. Fri, 17 Oct 2025 00:00:00 +0200 https://popups.uliege.be/2684-6500/index.php?id=285 https://popups.uliege.be/2684-6500/index.php?id=282 An equality-based weighted residual formulation is proposed for the periodic responses of vibrating systems subject to two-dimensional dry friction on a plane. Coulomb's law is expressed as two coupled nonsmooth equality conditions which augment the equations of motion, resulting in a mixed displacement-friction force formulation whose periodic solutions are sought using a standard Ritz-Galerkin procedure in time. The shape functions considered are the classical Fourier functions, and a quasi-analytical expression for the Jacobian of the friction terms is derived in a piecewise linear fashion and computed in a weighted residual sense. The method is based on an exact equality representation of Coulomb's law for interfaces with mass, thus avoiding common hypotheses such as regularization, penalization, or massless interfaces. It is entirely carried out in the frequency domain, contrary to existing frequency-time methods which require the calculation of contact forces in the time domain at each iteration of the nonlinear solver. The method is compact and found to be robust and accurate. It is void of convergence or other numerical issues up to very large numbers of harmonics of the response in all cases considered. Periodic responses featuring complex two-dimensional interface motions and multiple stick-slip transitions are calculated accurately at various resonant and sub-resonant excitation frequencies, at a reasonable computational cost. Since the only approximation in the procedure is the finite number of terms in the Ritz-Galerkin expansion, the intricate behavior of the two-dimensional friction force dictated by Coulomb's law can be captured with a high degree of accuracy. Wed, 27 Aug 2025 00:00:00 +0200 https://popups.uliege.be/2684-6500/index.php?id=282