Stiffness Of Layer Research Articles

Using Bender Elements to Investigate the Effect of a Multi-axial Geogrid on Aggregate Layer Stiffness

Geogrid inclusion in low-volume road applications has been shown to improve rutting performance. Although rutting performance and traditional instrumentation response data provide meaningful insights into pavement behavior, they do not provide a direct measurement of material behavior near the geogrid. Recently, the University of Illinois at Urbana-Champaign has developed field-deployable shear-wave transducers, that is, bender elements to measure the localized stiffness enhancement attributed to geogrid inclusion in unbound aggregate layers, which have been verified in laboratory and limited field applications. Bender element sensors were installed in a full-scale accelerated pavement test experiment at the U.S. Army Engineer Research and Development Center that included a recently developed multi-axial hexagonal geogrid. The sensors were installed directly on the geogrid and 10 cm above the geogrid in the unbound aggregate layer to measure the geogrid zone of influence. The test item was trafficked with a dual-wheel truck gear, and bender element measurements were made at select intervals throughout traffic application. To estimate the unbound aggregate moduli, the data were analyzed using two techniques: first arrival time and peak-to-peak arrival time. The bender element sensors were found to be sufficiently robust to survive installation, construction, and trafficking. Calculated modulus values 10 cm above the geogrid were found to be higher than those directly on the geogrid, which was an unexpected finding. However, a forensic investigation revealed moisture and fines migration into the bottom of the unbound aggregate layer, which could have dampened the shear-wave signal, resulting in lower calculated modulus values.

Hygromechanical behaviour of wooden panel paintings: classification of their deformation tendencies based on numerical modelling and experimental results

Wooden panel paintings are among the most important historical and artistic artworks from the Middle Ages and the Renaissance period. Currently, they represent a challenge for conservators and scientists who face complex issues related to their conservation. Panel paintings can be considered multilayer objects, that for brevity can be considered to consist of a wooden support and various paint layers. The wooden support is known to be hygroscopic and is continuously seeking hygroscopic equilibrium with the humidity of the environment, thus it tends to deform. Based on various hygroscopic tests carried out on 6 real panel paintings chosen by expert restorers to represent different periods and construction techniques, this paper describes the deformation tendencies of the selected panel paintings. Among possible variables, three most important variables were identified: (a) tree ring orientation of the wooden support, (b) stiffness and (c) emissivity of the paint layers. The internal equilibrium of the forces, governed by the moisture gradients across the thickness of the wood, changes drastically according to the varying characterisation of these factors. To observe their individual contributions, the 6 panel paintings underwent various humidity cycles, were completely free to deform and were always in complete safety. To characterise the stiffness and emissivity of the paint layers, the 6 panel paintings underwent a few humidity cycles with the front face totally waterproofed; thus, the moisture exchange was forced from the back only, and one of the three variables was eliminated. A complex system emerges where the tree ring orientation of the wooden support, the stiffness and emissivity of the paint layers are strongly coupled and determine the deformation modes of the panel paintings. A numerical analysis was conducted to classify the various general deformation modes of panel paintings and the specific classification of the 6 real panel paintings analysed experimentally. The complexity of the interaction of the variables studied suggests that experimental procedures must be conducted in preparation for numerical analyses of real panel paintings.

“Wood-nacre”: Development of a Bio-inspired Wood-Based Composite for Beam and 3D-Surface Elements with Improved Failure Mechanisms

Following the natural structure of the nacre, the material studied consists of a multitude of hexagonal tiles that are glued together in an offset manner with a ductile adhesive. This so-called “wood nacre” consists of macroscopic tiles of birch wood veneer with a thickness of 0.8 mm and a size of 20 or 10 mm in diameter in order to mimic the aragonite tiles and the ductile PUR-adhesive corresponds to the layers of collagen in between. E-modulus (MOE), bending strength (MOR) and impact bending strength of the samples were determined and compared with reference samples of birch laminated wood. The hierarchical layered structure of the tiles does not cause any relevant loss in stiffness. Like nacre, “wood nacre” also shows tough fracture behaviour and a high homogenization effect. However, strain hardening and high fracture toughness of the natural model could not be fully achieved. The reason for this is the insufficient ratio between the strength and stiffness of the veneer layers and the adhesive. By adjusting the size of the tiles, increasing the strength and surface roughness of the veneers, e.g. by densification, and using more ductile adhesives that can be applied in smaller layer thicknesses, it should be possible to better reproduce the natural ratios of nacre and thus achieve a significant improvement in the material properties of “wood nacre”. In addition to the mechanical properties, the high potential of the new material lies in the possibility of producing 3D shell-shaped elements for lightweight wood hybrid construction.

Variable Stiffness Actuators with Covalently Attached Nanofragments that Induce Mineralization

AbstractSoft robotics has attracted great attention owing to their immense potential especially in human–robot interfaces. However, the compliant property of soft robotics alone, without stiff elements, restricts their applications under load‐bearing conditions. Herein, biohybrid soft actuators, that create their own bone‐like rigid layer and thus alter their stiffness from soft to hard, are designed. Fabrication of the actuators is based on polydimethylsiloxane (PDMS) with an Au film to make a soft substrate onto which polypyrrole (PPy) doped with poly(4‐styrenesulfonic‐co‐maleic acid) sodium salt (PSA) is electropolymerized. The PDMS/Au/PPy(PSA) actuator is then functionalized, chemically and physically, with plasma membrane nanofragments (PMNFs) that induce bone formation within 3 days, without using cells. The resulting stiffness change decreases the actuator displacement; yet a thin stiff layer cannot completely stop the actuator's movement, while a relatively thick segment can, but results in partial delamination the actuator. To overcome the delamination, an additional rough Au layer is electroplated to improve the adhesion of the PPy onto the substrate. Finally, an alginate gel functionalized with PMNFs is used to create a thicker mineral layer mimicking the collagen‐apatite bone structure, which completely suppresses the actuator movement without causing any structural damage.

Comparative evaluation of dynamic responses of RCC composite pavement under different moving axles

Roller-compacted composite pavement is considered as an alternative for traditional pavements that provides the desired benefits of both rigid and flexible pavements in a cost-effective manner. To evaluate the performance of roller-compacted concrete (RCC) composite pavement under moving loads, a three-dimensional finite element model (FEM) was developed. A realistic dynamic moving load was applied to the surface of the pavement via DLOAD subroutines developed by FORTRAN. The dynamic response of the pavement at critical locations induced by single, tandem, and tridem axles at speeds of 8 and 80 km/h was determined using the developed FEM model and utilized to estimate pavement performance. Sensitivity analysis of design factors considering variations of hot mix asphalt (HMA) and RCC thicknesses, RCC elastic modulus, axle configurations, and moving speed was conducted to evaluate their impact on fatigue life and rutting development of RCC composite pavement. The results show that the performance of the pavement is significantly affected by axle configurations and moving speed. Among different axle configurations, the tandem axle creates the highest tensile stress and shear stress in the RCC base and HMA layer, respectively. The fatigue life of the pavement prolongs by increasing in the speed of moving loads, so it is expected that the pavement withstands higher load repetition when it is subjected to higher speed traffic. Moreover, increasing layer thicknesses and stiffness of the RCC layer improve fatigue life and rutting performance of the pavement. Even though increasing the thickness of the HMA layer enhances the fatigue life of pavement, increasing it to over 15 cm increases the potential of rutting.

Influence of Loading Rate on the Cohesive Traction for Soft, Rubber-Like Adhesive Layers Loaded in Modes I and III

To date, the fracture behaviour of soft, polyurethane-based adhesive joints has rarely been investigated. This work contributes to the experimental investigation of such joints in modes I and III by performing double cantilever beam (mode I) and out-of-plane loaded double cantilever beam (mode III) tests at various loading rates. The tests were evaluated using a J-integral method, which is well established for testing stiff adhesive layers and is conventionally used to determine the cohesive traction at the crack tip. Additionally, fibre-optics measurements were conducted to provide crack extension, process zone length, and cohesive traction from the measured backface strain of the adherends. It was found that the energy release rate seems to be largely independent of the loading mode. However, differences were observed regarding process zone length and resistance curve behaviour. Furthermore, the backface strain measurement allows the determination of the cohesive traction along with the complete adhesive layer as well as separation and separation rate, yielding rate-dependent cohesive laws. A comparison indicated that the cohesive traction obtained from the J-integral method does not match the measured benchmark from the backface strain measurements because the underlying theoretical assumptions of the J-integral method are likely violated for soft, rubber-like adhesive joints.

Undrained capacity of circular shallow foundations on two-layer clays under combined VHMT loading

Wind turbines are typically designed based on fatigue and serviceability limit states, but still require an accurate assessment of bearing capacity. Overconsolidated clay deposits in Canada often have a thin layer of crust with a relatively high undrained shear strength. However, existing bearing capacity design methods do not consider surficial crusts. This paper studies the undrained VHMT (vertical, horizontal, moment, and torsional) failure envelope of circular foundations founded on a surficial crust underlain by a uniform soil using finite element analysis. Crust correction factors have been introduced to account for the effects of the stiff layer on the vertical and moment capacities. The same forms of equation that are used for uniform soils, but with different parameters provide satisfactory fits for the failure envelopes for a soil with a crustal layer. An analytical expression for the 4-D VHMT failure envelope is derived, and an application of this method is provided.

Effectiveness of using liquid nitrogen cryogen in grinding to enhance the grinding performance of hard steel

Grinding generates a lot of heat in the grinding zone area during operation. Therefore, it is important to keep the temperature under control by using various cutting fluids to get a good ground surface quality. The existence of a stiff air layer surrounding the abrasive wheel is known to waste most of the cutting fluid supply in the interface area between the abrasive wheel and workpiece. Due to the high grinding speed, stiff air layers prevent cutting fluids from entering the interface area. Hence, to enhance the grinding performance, cryogenic cooling has been introduced to improve the penetration into the stiff air layer. The current work investigates the grindability of the ground surface of AISI D2 tool steel under different environments: dry, wet, and cryogenic, regarding grinding forces (i.e. tangential and normal force), specific grinding energy, and surface characterisation. This paper also proposed a method to evaluate image-based Abbott–Firestone curve (bearing area curve) parameters to characterise the ground surface topography. Significant reductions in grinding forces (64%–67% and 44%–50% in Ft, 54%–58% and 34%–39% in Fn), low specific grinding energy (64%–67% and 44%–50%), decrease in surface roughness (46%–51% and 30%–36% in Ra, 37%–41% and 31%–35% in Rz), improved 2D and 3D roughness profiles and higher bearing area ratio (89.54%) were observed at 40 µm downfeed in cryogenic cooling environments compared to dry and wet environments, respectively. Thus, observations show the importance of cryogenic cooling across the experimental domain.

Bladder Wall Stiffness after Cystectomy in Bladder Cancer Patients: A Preliminary Study.

Bladder cancer (BlCa), specifically urothelial carcinomas, is a heterogeneous disease that derives from the urothelial lining. Two main classes of BlCa are acknowledged: the non-muscle invasive BlCa and the muscle-invasive BlCa; the latter constituting an aggressive disease which invades locally and metastasizes systemically. Distinguishing the specific microenvironment that cancer cells experience between mucosa and muscularis propria layers can help elucidate how these cells acquire invasive capacities. In this work, we propose to measure the micromechanical properties of both mucosa and muscularis propria layers of the bladder wall of BlCa patients, using atomic force microscopy (AFM). To do that, two cross-sections of both the macroscopically normal urinary bladder wall and the bladder wall adjacent to the tumor were collected and immediately frozen, prior to AFM samples analysis. The respective "twin" formalin-fixed paraffin-embedded tissue fragments were processed and later evaluated for histopathological examination. H&E staining suggested that tumors promoted the development of muscle-like structures in the mucosa surrounding the neoplastic region. The average Young's modulus (cell stiffness) in tumor-adjacent specimens was significantly higher in the muscularis propria than in the mucosa. Similarly, the tumor-free specimens had significantly higher Young's moduli in the muscularis propria than in the urothelium. Young's moduli were higher in all layers of tumor-adjacent tissues when compared with tumor-free samples. Here we provide insights into the stiffness of the bladder wall layers, and we show that the presence of tumor in the surrounding mucosa leads to an alteration of its smooth muscle content. The quantitative assessment of stiffness range here presented provides essential data for future research on BlCa and for understanding how the biomechanical stimuli can modulate cancer cells' capacity to invade through the different bladder layers.

A strategy improving stiffness to resist local vibration of sandwich plates by extended Legendre higher-order model

Sandwich structures have been increasingly used in aerospace engineering, while local vibration modes of sandwich plates might occur earlier than global vibration modes attributing to the weak stiffness of the core layer, and it is difficult to predict such vibration modes. Therefore, local vibration modes are often discarded in the process of structural design, so that potential dangers might be encountered when the frequency of external load is close to the natural frequency of local vibration. To avoid such an issue, an extended Legendre higher-order theory (ELHT) is developed to accurately forecast the local dynamic behaviors of sandwich plates for the first time. Subsequently, an effective multi-objective optimization platform will be constructed to optimize the distribution of graphene-nanoplatelets (GPLs) in the core layer, so that natural frequencies of local vibration modes will be improved and largely more than the fundamental frequency. The B-spline basis functions are employed to describe various GPLs distributions, which is more convenient to produce original data for the machine learning method in the optimization process. Then, extreme gradient boosting optimized by Sparrow Search Algorithm (SSA-XGBoost) is utilized as the high-fidelity surrogate model to construct the objective functions to accelerate the interaction of the ELHT and non-dominated sorting sparrow search algorithm (NSSSA). By optimizing for minimum global and local fundamental frequency ratio and total mass of GPLs reinforced sandwich plates, the Pareto-optimal solutions are obtained from the present algorithm which can give an alternative suggestion for the future designer to ensure the structural dynamic safety of thick sandwich plates.

The relationship between structure and rheology in a three-dimensional sheared lamellar mesophase.

The evolution of a lamellar mesophase from an initially disordered state under shear is examined using simulations of a mesoscale model based on a concentration field ψ that distinguishes the hydrophilic and hydrophobic components. The Landau-Ginzburg free-energy functional is augmented by a term that is minimised for sinusoidal modulations in the concentration field with wavelength λ = (2π/k), and the dynamical equations are the model H equations. The structure and rheology are determined by the relative magnitudes of the diffusion time for coarsening, (λ2/D) and the inverse of the strain rate -1, and the Ericksen number, which is the ratio of the shear stress and the layer stiffness. When the diffusion time is small compared with the inverse of the strain rate, there is a local formation of misaligned layers, which are deformed by the imposed flow. There is near-perfect ordering with isolated defects at low values of the Ericksen number, but the defects result in a significant increase in viscosity due to the high layer stiffness. At high values of the Ericksen number, the concentration field is deformed by the mean shear before layers form via diffusion. Cylindrical structures aligned along the flow direction form after about 8-10 strain units, and these evolve into layers with disorder through diffusion perpendicular to the flow. The layers are not perfectly ordered, even after hundreds of strain units, due to the creation and destruction of defects via shear. The excess viscosity is low because the layer stiffness is small compared with the applied shear at a high Ericksen number. This study provides guidance on how the material parameters and imposed flow can be tailored to achieve the desired rheological behaviour.

Forced Vibration Analysis of Euler-Bernoulli Double-Beam Systems by Means of Green’s Functions

Double-curved-beam (DCB) systems are usually seen in many engineering fields. Compared to straight double-beam systems, DCB systems are more efficiency in noise and vibration control problems. This work aims to obtain closed-form solutions of steady-state forced vibrations of DCBs. The classical Euler-Bernoulli curved beam (ECB) model is employed in this work to modelling vibration equations of the DCB systems. The Green’s function and Laplace transform methods are successively used to obtain fundamental solutions for the vibration equations of the DCB systems. In this work, the fundamental solutions are general solutions and can be used for any boundary conditions. In numerical section, the present solutions are verified by comparing to some results in references. Effects of some important geometric and physical parameters on vibration responses and the interaction between the stiffness of the elastic layer and the DCB system are discussed. The results show that the DCB system can be degenerated to the straight double-beam system by setting two radiuses to infinity, and the DCB system also can be reduced to a double-beam system whose one upper or lower beam is a straight beam and the other is a curved beam.

Structural health monitoring for layered structure using a force identification approach

In this study, we proposed a structural health monitoring and diagnostic method for layered structures using the force identification of approach. This method belongs to the primary diagnosis one, and its purpose is to identify the location of abnormality quickly after abnormality detection. A feature of this method is that the displacement change caused by an abnormality in the structure is considered by applying additional force to the normal structure. In the early stage of abnormality, the stiffness of a certain layer will change, so the local additional force is identified, and the accuracy of the reconstructed displacement change is estimated. In the diagnosis of an actual structure, the actual vibration characteristics may differ from those obtained by the mathematical model. We also proposed a method for predicting the frequency response function in the abnormal state based on the difference between the actual measurement and the mathematical model in the normal state. First, we considered a five-layered structure as a numerical example and validated the proposed method. When we applied the method to three types of abnormal conditions, we found that the abnormality could be diagnosed correctly. Next, we constructed an experimental model of a five-layered structure and verified the applicability of the proposed method. We created a type of abnormal condition and showed that the abnormality could be diagnosed correctly. As described above, the validity and applicability of the proposed method were clarified.

A stochastic approach on modeling the long-term unevenness of pavements considering spatially varying soil properties/Ein stochastischer Ansatz zur Modellierung der langfristigen Entwicklung von Fahrbahnunebenheiten unter Berücksichtigung räumlich variierender Bodeneigenschaften

Even within nominally homogenous soil layers, spatial variations of soil properties occur. Current design methods simplify varying soil properties by applying constant values. In order to achieve a reliable geotechnical design, the local variance of soil properties needs to be considered with respect to the long-term development of road unevenness. Hence, a variation of soil stiffness leads to spatially varying settlements and increasing dynamic forces on passing vehicles as time increases. This process continues steadily resulting in a noticeable reduction of driving comfort until a repair of the pavement is required. In this paper, a numerical model is applied to determine the long-term unevenness of pavements considering the spatial variation of soil properties. Thereby, the asphalt pavement, the subbase, and the subgrade are modeled by a set of coupled spring elements representing the soil behaviour of the respective layer. A stochastic distribution of soil properties based on a random walk is assumed to account for the spatial variation of the subsoil stiffness. The long-term unevenness development due to passing vehicles is extensively evaluated with respect to resulting dynamic forces and the impact of a deviating soil stiffness in individual soil layers. Finally, conclusions with respect to driving comfort are drawn.

Improving sustainability of road construction by partial replacement of natural aggregates in subbase layer with crushed brick and reclaimed asphalt pavement

Reducing dependent on naturally sourced materials is among the priority in improving the sustainability of road construction. The subbase layer which provides strength and stability across the road profile, comprised mainly of natural aggregates. This study aims to explore the feasibility of partial replacement of natural aggregates in subbase layer with 20% Crushed Brick (CB) and 20 to 50% Reclaimed Asphalt Pavement (RAP). California Bearing Ratio (CBR) test and Constant Head Permeability tests were carried out to determine the effect of this partial replacement on the geotechnical properties of the subbase layer. The results obtained denotes that the combination of 20% CB and 50% RAP is the optimum partial replacement of natural aggregates in subbase layer with CB and RAP. The use of CB further complements RAP in improving the stiffness and compressibility of the subbase layer while contributing significantly toward sustainability in road construction.

Можливості стандартних методів випробування дорожніх одягів навантаженням

The standard methods for testing road pavements by loading have been widely applied to assess the road pavements maintenance during design, construction and survey stages and especially for the Pavement Management System purposes. These test methods were classified by the type of an applied load as static loading, cyclic loading or impulse loading tests. The paper reviews the above mentioned test methods from the aspects of their scopes, advantages, and general requirements for testing in accordance with the world-wide experience in road building industry. Static loading shall be positioned as the simplest and low-cost test method that permits the testing of relatively thick pavement constructions but does not allow the measurements of deflection bowl. Cyclic loading is more convenient for thinner pavements testing and, together with surface moduli, permits the measurements of deflection bowl. Impulse loading is the most representative test method that simulates traffic loading most adequately and permits the deflection bowl measurements as well. Impulse load can be applied using “high-weigh” device such as falling weight deflectometer, or light weight deflectometer thus given the possibility for testing road pavements with a monolithic upper layer or an unbound layer (base layer, sub-base, sub-grade layer). Standard methods for testing road pavements by loading were widely implemented to measure the surface moduli, the deflection bowl values and also, for rigid pavements, the load transfer efficiency in an area of joint or crack. Surface moduli and deflection bowl values are effectively used, mainly through the back-calculation processes, to assess the stiffness of pavement layers, the life span of road pavements and also for the project or network level testing of road pavements. These tasks rise as high actual for Ukraine intended to be integrated in the EU transport system, where trucks weighing up to 40 tonnes are permitted for international hauling. Considering the necessity for expansion of network level testing to assess the bearing capacity of road pavements and to set restrictions for trafficking at some critical conditions especially seasonal those, the conclusions state the need to process related national standards as national normative documents aiming on: – implementation of standard international classification of methods for testing the road pavements by loading considering the type of loading; – widening the requirements for proceeding of tests; – improvement the pavement management system. Keywords: road pavement; non-destructive testing; static loading; cyclic loading; dynamic loading.

Influence of self-cementing properties on the mechanical behaviour of recycled concrete aggregates under monotonic loading

Recently, the use of recycled crushed concrete aggregates (RCA) as a substitution of natural aggregates in pavement base and subbase layers has become more popular. Occasionally, a growth of stiffness and strength in unbound base and subbase layers built with RCA can be observed, which can be considered as self-cementing properties of RCA. In this study, the potential self-cementing properties and the long-term mechanical behaviour of two different RCA (NRCA and ORCA), with significantly different self-cementing properties, were studied by pH value, thermogravimetric analysis (TGA) and monotonic triaxial tests under varying confining pressures (20/40/70 kPa) and varying curing times (1/28/360 days). Results show that the long-term storage can largely reduce the self-cementing properties of RCA (ORCA), while the RCA crushed recently (NRCA) exhibits much stronger self-cementing properties. Besides, the long-term mechanical behaviours are influenced by self-cementing properties and confining pressure as well as curing time, so that the strength and stiffness of RCA specimen, with stronger self-cementing properties (NRCA), increase more under low confining pressure and long curing time. The experimental results also indicate that the long-term mechanical behaviours of NRCA are consistent with cement treated materials, whose ductile stress–strain response gradually turns to stiff brittle behaviour as curing time increases.

Sustainable pavement with geocell reinforced reclaimed-asphalt-pavement (RAP) base layer

According to the Federal Highway Administration Policy, recycled material should be the highest priority in selecting pavement materials. However, the quality of the reclaimed/recycled material should meet the minimum standard to ensure long-term benefits. This study uses geocell to enhance the performance of reclaimed asphalt pavement (RAP) material. Three pavement test sections were constructed with 0.15, 0.20, and 0.30m thick geocell reinforced RAP bases (GRRBs) by replacing the existing base layer of a farm-to-market road located in the southern part of Fort Worth, Texas, USA. These test sections were monitored for a period of three years to evaluate the pavement performance in terms of rutting, cracking, and riding quality. In addition to the regular monitoring falling weight deflectometer (FWD) tests were also conducted to determine the base layer modulus. Results showed that the geocell layer reduced the permanent deformation by at least 36% compared to the unreinforced section. The application of geocell also helped control the test sections' bottom-up longitudinal cracking by providing uniform support. The FWD test revealed that the geocell enhanced the GRRB layer stiffness by 20%. The construction cost of the GRRB layer was 22.9% less than the traditional flex base layer. Replacement of flex base material with GRRB material could reduce the emission of CO2 by 37 tons for each lane-km.

Microparticle Impact Testing at High Precision, Higher Temperatures, and with Lithographically Patterned Projectiles.

In the first decade of high-velocity microparticle impact research, hardly any modification of the original experimental setup has been necessary. However, future avenues for the field require advancements of the experimental method to expand both the impact variables that can be quantitatively assessed and the materials and phenomena that can be studied. This work explores new design concepts for the launch pad (the assembly that launches microparticles upon laser ablation) that can address the root causes of many experimental challenges that may limit the technique in the future. Among the design changes contemplated, the substitution of a stiff glass launch layer for the standard elastomeric polymer layer offers a number of improvements. First, it facilitates a reduction of the gap between launch pad and target from hundreds to tens of micrometers and thus unlocks a reproducibility in targeting a specific impact location better than the diameter of the test particle itself (±1.75 µm for SiO2 particles 7.38 µm in diameter). Second, the inert glass surface enables experiments at higher temperatures than previously possible. Finally-as demonstrated by the launch of thin-film Au disks-a launch pad made of materials standard in microfabrication paves the way to facile microfabrication of advanced impactors.

Nonlinear Dynamics of a Resonant-Impact Dielectric Elastomer Actuator

In recent years, with the rapid development of soft robots, dielectric elastomer actuators (DEAs) as a novel type of soft actuators have been widely studied. However, DEAs often suffer from low instantaneous output force/power, especially in high payload damping conditions, which limits their applications in certain scenarios. Inspired by the vibro-impact mechanisms found in many engineering systems (e.g., pile driving and percussive drilling), a resonant-impact DEA system was proposed in the authors’ previous work to potentially address this limitation. However, due to the complex nonlinearities and unique electromechanically coupled forcing mechanism of DEAs, no nonlinear dynamic model was developed to perform systematic investigations and optimization. In this paper, a nonlinear dynamic model of the resonant-impact DEA system is developed by considering multiple nonlinearities, viscoelasticity, and electromechanical coupling. Using both a numerical model and extensive experiments, the nonlinear dynamics of the resonant-impact DEA system are studied in depth. The effects of several key parameters, including excitation voltage amplitude, constraint gap, constraint stiffness, and number of DEA layers, on the dynamic response of the system are characterized. The findings reported in this paper can provide guidance for the performance optimization of resonance-impact DEA systems and their applications.