Vacuum Packed Particles Torsional Dampers (VPPTDs) are adaptive devices capable of providing tunable damping through the adjustment of under pressure inside a granular-filled chamber. Despite their promising applications in vibration control, accurately modeling their highly nonlinear and hysteretic behavior remains a significant challenge. This paper shows a modified Bouc-Wen model that incorporates an additional nonlinear stiffness term and a dry friction component to better represent the torque-angular displacement relationship under varying operational conditions. Quasi-static experiments were conducted on a dedicated test stand with harmonic excitation (+/- 10 degrees) across frequencies from 0.0 to 0.8 Hz and under pressures ranging from 0.00 to 0.09 MPa. Various granular mixtures composed of Acrylonitrile Butadiene Styrene (ABS) and Nitrile Butadiene Rubber (NBR) particles in volume ratios of 1:0, 3:1, 1:1, 1:3, and 0:1 were investigated. The shape and area of the hysteresis loops were found to depend strongly on both the mixture composition and the vacuum level. Model parameters were identified using evolutionary algorithms and expressed as functions of under pressure, allowing the simulation of pressure-dependent damping and stiffness behavior. Dynamic simulations based on the identified models confirmed that adjusting the vacuum level effectively changes the system dynamic response. The results demonstrate that the proposed model reliably captures the complex hysteretic behavior of VPPTDs and confirms the feasibility of employing under pressure as an effective control variable in adaptive damping applications.

This study investigates the dynamic behavior of a vacuum packed particles torsional damper (VPPTD) filled with a 1:3 plastic (ABS-acrylonitrile butadiene styrene) and rubber (NBR-nitrile butadiene rubber) granulate mixture. Experimental results revealed that the system exhibits a symmetric hysteresis loop, with maximum torque increasing systematically with applied underpressure. The response was characterized by viscous damping, linear and nonlinear stiffness, and friction-related torque. The main novelty of the paper is the implementation of the physics-informed neural network (PINN) to accurately identify model parameters based on experimental data. In addition, to final parameter identification, a detailed analysis of the training process was conducted, revealing how the model progressively converged toward the experimental hysteresis loop. The identified model showed good agreement with measured data, and theoretical model. Parametric trends revealed a near-linear dependence of all model parameters on underpressure. These findings suggest that the model can be generalized by expressing parameters as functions of underpressure, paving the way for adaptive, pressure-aware control strategies.

The paper presents an original design solution for a semi-active torsional damper filled with granular material. The main working element of the damper is the so-called Vacuum Packed Particles—a loose granular material placed in a sealed space where partial vacuum is created (activating the jamming mechanism). Internal pressure changes allow for the real-time, controlled modification of the device’s dissipative properties. Experimental investigations of the damper filled with rubber grains are presented. A mathematical model was applied to describe the experimental data, enabling the capture of damage and fatigue phenomena occurring in the damper. Based on the identified mathematical model, numerical simulations for standard operational damper conditions were conducted.

This paper presents the modelling and identification of hysteretic behaviour in a Vacuum Packed Particles Torsional Damper (VPPTD) filled with ABS (Acrylonitrile Butadiene Styrene) polymer granulate. The presented device is an innovative member of the semi-active damper family, featuring real-time controllable damping characteristics. A series of experiments were conducted to observe the response of the damper under various loading conditions. The Modified Bouc-Wen model (MB-W) was employed to capture the non-linear hysteretic characteristics exhibited by the damper. Using an evolutionary algorithm, the parameters of the model were identified on the basis of experimental data. The identified parameters of the Modified Bouc-Wen model are described by underpressure functions. The proposed model was validated, demonstrating its efficacy in predicting the damper's hysteretic behaviour under various operating conditions. This study contributes to the understanding and prediction of complex non-linearities in VPPs.

The paper presents a novel approach for the modeling of the Adaptive Tuned Particle Impact Damper (ATPID) using Multilayer Perceptron (MLP). The main motivation was the recognition that such an approach can support the development of novel neural modeling and the optimal determination of damper parameters in terms of mechanical vibration attenuation. The training data were obtained using a theoretical model validated experimentally. The optimally selected MLP was compared with other regression models using 10 different metrics. A hyperparameter tuning of the determined neural network architecture was conducted based on the input parameters such as excitation amplitude, grain mass, and ATPID damper height. The analyses show that the proposed neural network could quickly and accurately estimate the system's vibration amplitude and efficiently predict the optimal damper height. The ability to effectively determine the correct optimal height is crucial for ATPID damper control. The high efficiency in predicting the system's vibration amplitude allows for the replacement of the theoretical model with applied time-consuming contact forces. The MLP accurately estimated vibration amplitudes with 1%-10% error for interpolated data and up to 15% for extrapolated cases. The issue raised is particularly important from the perspective of real-time damper control. It was found that computing a single case using the artificial neural network is more than ten times faster compared to the theoretical model. Therefore, the proposed ATPID damper model based on a neural network forms the basis for further considerations and scientific research to finally propose a control algorithm in the future.

In this work, we investigate Vacuum-Packed Particle (VPP) dampers - granular-core dampers offering tunable damping performance under varying vacuum levels. A comprehensive computational model of the entire VPP damper system is developed using the Discrete Element Method (DEM). A novel discrete-element model of the flexible foil, responsible for consistently transmitting the external pressure resulting from vacuum application, is introduced and implemented by extending the open-source Yade DEM framework. A prototype VPP damper is also designed and experimentally tested, enabling both model calibration and validation of the simulation results. The calibrated DEM model is subsequently employed in a parametric study to assess the influence of material, geometrical, and process parameters on damper performance. All code, along with the associated experimental and simulation datasets, is made available in an open-access repository.

This paper presents a novel predictive control strategy for the Adaptive Tuned Particle Impact Damper (ATPID), aimed at improving vibration suppression in systems with limited available information. The proposed control algorithm, called the Predictive Control Algorithm (PCA), is based on the prediction and optimization of system dynamics and operates effectively even when system parameters and external excitations are unknown. The only available input for the control process is the measured vibration response of the system. Under this constraint, the PCA accurately estimates the optimal height of the damper in real time, achieving vibration reduction of up to 75%. The algorithm also exhibits a second operational mode: when a theoretical model of the mechanical system is available, the PCA can incorporate this additional knowledge to further enhance control accuracy and performance. The algorithm's two operating approaches enable its application in a wide range of engineering environments. The robustness of the approach is further validated through sensitivity analyses investigating the impact of variations in particle mass, excitation amplitude, and gravitational conditions. The results obtained from the PCA algorithm show that the height prediction error remains below 10%, with accuracy increasing in conditions of higher excitation and particle mass. The main novelty of this work is the development of a versatile and fully adaptive predictive control algorithm for ATPID systems, capable of optimizing damper parameters based solely on vibration feedback but also leveraging mathematical system models when available. The proposed control algorithm represents important progress in the development of adaptive mechanical structures employing particle impact damping technology.

The rapid development of research on innovative soft robots has been observed in recent years. Most of these robots are equipped with mechanisms that enable adaptive stiffness changes. Although various physical effects facilitate this capability, one of the most intriguing is undoubtedly the granular jamming phenomenon. Structures based on this effect consist of granules enclosed within an elastomer sleeve, with stiffness controlled by vacuum pressure. This work focuses on investigating the properties of such structures subjected to cyclic loading under different stress states. We conducted a wide range of empirical tests under various loading conditions, including compression, tension, and bending. Based on this research, a constitutive equation was proposed to describe this phenomenon. The model was implemented into commercial finite element (FE) software, and numerical predictions were validated with empirical results. Finally, a new concept for a soft robotic gripper utilizing granular jamming as a stiffening mechanism was proposed and tested.

The paper presents a novel approach for prototyping and modelling of the Adaptive Tuned Particle Impact Damper (ATPID). After introducing the operation and potential disadvantages of the classical Particles Impact Dampers (PIDs) the authors propose the concept of single-grain controllable damper, which can adapt to actual dynamic excitation by a real-time change of the container height. The investigations focus on the methodology of simplified mathematical modelling of the ATPID damper based on grain physical properties, nonlinear soft contact theory, and control function of the absorber height being a novel component used to optimize dynamic response of the system. The proposed ATPID model is positively verified against the experimental results obtained from the developed test stand including a vibrating beam equipped with the proposed innovative attenuator. The conducted analyses clearly reveal the operating principles of the ATPID damper, the types of grain movement, the influence of shock absorber parameters on the vibrating system response and the energy balance of the system. The solution of the formulated optimization problem aimed at minimization of vibration amplitudes allows to find the optimal damper height for various physical parameters of the grain and the external excitation and to achieve a high efficiency of the proposed damper reaching 90%. In addition, a real-time control strategy providing adaptation of the ATPID damper to changing amplitude of kinematic excitation and effective mitigation of steady-state vibrations is proposed and verified experimentally.

The following discussion concerns the use of innovative smart materials called vacuum-packed particles (VPPs) as active energy absorbers. VPP, also known as a granular jamming system, is a structure composed of granular media contained within an elastomer coating. By changing the vacuum pressure inside the coating, it is possible to control the mechanical properties of the structure. VPPs have many applications, e.g. in medicine, robotics, and vibration damping. No attempts have yet been made to use VPPs to absorb the energy of a collision, although, given their properties, this could very well be an interesting application. In the first part of the paper, the general concept of the absorber is presented. Then a prototype and the empirical tests conducted are precisely described. The middle part of the paper considers the basic properties of VPP and modeling methodology. A proposal for a constitutive equation is presented, and a numerical simulation using LS-Dyna was performed. In the final section, the concept of a smart parking post is presented..

This article describes the cyclic loading of jammed granular systems represented by vacuum-packed particles in compression and tension, focusing on the influence of the properties of the granular material on the mechanical response. A jammed granular system is represented by a cylindrical sample filled with polymer granules (vacuum-packed particles) and is examined in symmetric cyclic compression and tension for up to 2000 cycles and at selected values of underpressure, i.e., 0.01, 0.04 and 0.07 MPa. Force and displacement are analyzed during the test, as well as changes in granule morphology by means of microscopic observations. The conducted tests indicate that it is possible to acquire repetitive results of maximum forces in the analyzed loading rage with the condition that granules do not plasticize during loading, i.e., they are resistant to damage during loading.

This paper presents experimental studies on a controllable granular damper, whose dissipative properties are provided by the friction phenomenon occuring between loose granular material. In addition, in order to adjust to the current trends in vibration suppression, we built a semi-active device, controlled by a single parameter—underpressure. Such granular structures subjected to underpressure are called Vacuum-Packed Particles. The first section presents the state of the art. A brief description of the most often used intelligent and smart materials for the manufacture of dampers is presented. The main advantages of the proposed device are a simple structure, low construction cost, symmetrical principle of operation, and the ability to change the characteristics of the damper by quickly and suddenly changing the negative pressure inside the granular core. The second section provides a detailed description of the construction and operation principles of the original symmetrical granular damper. A description of its application in the laboratory research test stand is also provided. The third section presents the results of the experimental studies including the recorded damping characteristics of the investigated damper. The effectiveness of the ethylene–propylene–diene grains’ application is presented. The two parameters of underpressure and frequency of excitation were considered during the empirical tests. The influence of the system parameters on its global dissipative behavior is discussed in detail. The damper operation characteristics are close to linear, which is positive information from the point of view of the potential adaptive-passive control process. Brief conclusions and the prospective application of vacuum-packed particle dampers are presented in the final section.

Vacuum-packed particle (VPP) systems have been recently used in the development of smart structures due to their ability to actively change material stiffness through the mechanism of granular jamming. By altering the strength of the vacuum pressure applied to the particles, the material can be proportionally and reversibly transitioned from a liquidlike low-stiffness state to a stiff state. The ability to control material stiffness in this way opens up different possibilities for the design of morphing and smart structures by allowing them to soften during deformation to reduce actuation energy requirements and to then stiffen once the desired shape has been achieved to provide a zero-energy holding mechanism. The following research describes two useful models that predict the mechanical response of VPP beams under flexural loading. Firstly, four-point bending tests with digital image correlation strain mapping are performed in order to measure the axial and transverse strains in a bending beam made from vacuum-packed particles. The test results show a nonlinear mechanical response, including a change in beam thickness with deformation, that motivated an analytical model of the structure incorporating a nonlinear material stress model based on the Mohr-Coulomb failure envelope. In addition, finite-element simulations are implemented using a Johnson-Cook model extension to predict the response under loading of three-dimensional beam elements at different vacuum pressure levels. Lastly, the models are compared to the experimental results, indicating good agreement. Both methods are shown to be useful for predicting the variation of stiffness of vacuum-packed particle beams.

This paper concerns the problem of empirical investigation and mathematical modelling of a novel controllable damper using vacuum packed particles. Vacuum packed particles tend to be placed among the group of so-called ‘smart structures’. The macroscopic mechanical features of such structures can be controlled by the partial vacuum parameter. The authors consider an application of Bouc-Wen model in order to represent the dynamic behaviour of the investigated device. The verification of the model response with experimental data is discussed. The Bouc-Wen model parameters identification is described.

The paper presents a prototype of an innovatory controllable torsional damper. The device is composed of Vacuum Packed Particles. Such structures are made of granular materials placed in a hermetic soft encapsulation. Generating so called underpressure inside the system changes global dissipative properties of the granular structure. The partial vacuum value is a convenient way to control physical properties of the granular structure. The authors introduce an original prototype of a torsional vibration attenuator. In the experimental part, preliminary experimental results are presented and discussed. To capture the real response of the device, a Bouc-Wen rheological model is adopted.

Jammed granular systems, also known as vacuum packed particles (VPP), have begun to compete with the well commercialized group of smart structures already widely applied in various fields of industry, mainly in civil and mechanical engineering. However, the engineering applications of VPP are far ahead of the mathematical description of the complex mechanical mechanisms observed in these unconventional structures. As their wider commercialization is hindered by this gap, in the paper the authors consider experimental investigations of granular systems, mainly focusing on the mechanical responses that take place under various temperature and strain rate conditions. To capture the nonlinear behavior of jammed granular systems, a constitutive model constituting an extension of the Johnson–Cook model was developed and is presented. green The extended and modified constitutive model for VPP proposed in the paper could be implemented in the future into a commercial Finite Element Analysis code, making it possible to carry out fast and reliable numerical simulations.

The paper presents a prototype of an innovatory controllable torsional damper. The device is composed of Vacuum Packed Particles. Such structures are made of granular materials placed in a hermetic soft encapsulation. Generating so called underpressure inside the system changes global dissipative properties of the granular structure. The partial vacuum value is a convenient way to control physical properties of the granular structure. The authors introduce an original prototype of a torsional vibration attenuator. In the experimental part, preliminary experimental results are presented and discussed. To capture the real response of the device, a Bouc-Wen rheological model is adopted.

The most popular devices for attenuation of mechanical vibrations are dampers or shock absorbers. Two main energy dissipation strategies can be generally distinguished: passive and active (semi-active). Passive vibration isolation methods are the most commonly used, mainly because of their simplicity and low maintenance costs. Among passive vibration attenuation techniques, also Particle Impact Dampers (PID) are involved. Classical PID solutions have some certain limitations. This paper aims at presenting the new concept of an adaptive tuned PID damper that can pretend to be placed among semi-active energy dissipation methods.

The presented paper reveals an innovative device which is the Tuned Particle Impact Damper (TPID). The damper enables the user change the dynamical features of the vibrating system thanks to rapidly tuning the volume of the container where the grains are locked. The effectiveness of proposed semi-active damping methodology was confirmed in experiments on vibrations of a cantilever beam excited by kinematic rule. Various damping characteristics captured for different volumes of the grains container and mass of granular material are presented. It is confirmed that the proposed TPID device allowed for efficient attenuation of the beam's vibration amplitude in the range of its resonant frequency vibrations.

This paper presents the challenges faced in modelling marine operations with a particular focus on lifting in air. Those challenges are looked at from a purely modelling perspective showing various approaches encountered in the literature. Paper further discusses the disadvantages of those models and proposes a 3-DOF solution that allows to observe all of the physical phenomena and their possible relation enabling efficient, in-depth studies of the operations in discussion. The proposed model is presented in detail starting from a computation of excitation, through the numerical approach with a variety of interesting results. An advantage of the presented approach is seen in the analytical modelling what allows for a theoretical, numerical and combined analysis. The model allows for an implementation of a variety of excitation types providing an ability to study responses to regular and irregular wave. A phenomenon of a parametric resonance was discovered what allows for a reliable assessment of dynamic behaviour, emphasising another advantageous feature of the model in comparison to other approaches discussed. Paper is concluded by a validation of the proposed methodology. It is also suggested that the model proposed is a good, computationally viable, easily accessible balance between overly simple and overly complex models.