Shock Loading Research Articles

A large deformation multiphase continuum mechanics model for shock loading of soft porous materials

AbstractA large deformation, coupled finite‐element (FE) model is developed to simulate the multiphase response of soft porous materials subjected to high strain‐rate loading. The approach is based on the theory of porous media (TPM) at large deformations. Simplifications to the one‐dimensional regime studied in the numerical simulations follow. An overview of several different time integration schemes is presented for the purpose of solving the nonlinear dynamic coupled balance of momenta (mixture and fluid) and balance of mass of the mixture equations. Numerical examples are presented for (i) verification against closed‐form analytical solutions assuming small loads, (ii) demonstrating large deformation effects at high strain‐rate, and (iii) showing differences in deformations between a single‐phase elastodynamics model with occluded compressible pore fluid and a multiphase poroelastodynamics model at high strain‐rate. The multiphase model shows that the relative motion of the pore fluid significantly dampens the deformation response of the solid skeleton as compared to the single‐phase model, and makes it possible to extract quantitative values for the stresses of the different constituents, thereby allowing one to form preliminary conclusions about the onset of damage in the solid skeleton. The novelty of the current work is developing a multiphase, large deformation, mixture theory numerical model for high strain‐rate loading of soft porous materials. It was discovered that explicit, adaptive time‐stepping Runge–Kutta schemes offer high accuracy at relatively low cost when compared to traditional implicit or explicit central difference time‐stepping schemes for shock‐like loadings. Shock viscosity is added to the mixture momentum balance equation to regularize the shock front, and a stabilization term is added to the mixture mass balance equation to stabilize equal order interpolation finite elements for the coupled finite element solution of multiphase materials.

Influence of iron anisotropy on phase transition near grain boundary under shock

As is well known, iron plays an important role in the fields of national defense and industry, so it is of great significance to study its behavior under dynamic high pressure. As one of the most common defects in metals in nature, grain boundaries have an important influence on the mechanical properties and deformation of materials under shock. This work intends to use large-scale non-equilibrium molecular dynamics simulation to study the influence of iron anisotropy on the phase transition in bicrystal under shock loading. By tracking the local structure, shear stress distribution and morphology characteristics after shock on both sides of the grain boundaries, the factors affecting the response on both sides of the grain boundary are analyzed. Our research result shows that shocking along the non-centrosymmetric grain direction can cause significant differences in the phase transition threshold, path and mode on both sides of the symmetric grain boundary. Especially, the different phase transition dynamic processes on both sides of the sigma11 grain boundary are discussed in detail in this work, which have been rarely discussed in previous studies. Considering the symmetry of the microstructure on both sides of this type of grain boundary, the result of asymmetric shock response is different from people’s inertial cognition. Finally, it is found that the atoms in both models will shift along the direction perpendicular to the shocked direction under shock, indicating that the shock wave generated by the piston method should no longer be simply regarded as one-dimensional when shocked along the non centrosymmetric crystal direction, and the displacement of atoms along the direction perpendicular to the shocked direction is closely related to the symmetry of the crystal, which causes significant differences in shear stress on both sides of the grain boundary and ultimately affects the shock response. This study reveals that the anisotropy of lattice has an important effect on the phase transition on both sides of grain boundaries under shock loading, which can provide theoretical support for the experimental studies of polycrystalline metals and alloys under shock.

Dynamic Response Analysis of Reinforced Column Subjected To Shock Wave Loading

This study focuses on the dynamical response of reinforced concrete members subjected to shock-wave loading, which can cause catastrophic damage to structures. The effects of high strain rate loading and lateral confinement on the member’s behavior are considered in the analysis. The Moment-Curvature (M-ϕ) relations are assessed using stress block equilibrium at yield and ultimate state, and an analytical model is developed that integrates the high strain rate material behavior to predict the peak deflection of the structural member. The study evaluates the dynamic response of the member using a simplified model based on single degree of freedom (SDOF) idealization, and the response of the member in elastic and elastic-plastic phases is modelled using the bilinear resistance function. The governing equation of motion is explained using the Newmark-Beta algorithm, and the shock spectrum predicting the maximum deflection is developed by varying the load duration and magnitude. Additionally, a Finite Element (FE) model is developed to provide a more detailed understanding of the member’s behavior under shock loading. The results obtained from the FE model are compared with the analytical deflection for extreme combinations of load duration and magnitude. The study provides valuable insights into the behavior of reinforced concrete members under extreme loads, which can help structural designers in predicting and design structures that can withstand such loading conditions. The results can also be used in the development of building codes and standards to improve the safety and resilience of structures subjected to shock-wave loading.

Optimal design of honeycomb battery pack enclosure for electric vehicle

A lithium-ion battery pack enclosure which consists of batteries is the prime source of energy for battery electric vehicles, BEV. While electric vehicle is in running condition, the battery enclosure comes across the worst scenarios like the vibrations coming from the road and impact because of road surface variations. These will cause structural stresses and variations in deformations for the enclosure structure. Electric vehicle safety wholly depends on how safe its battery pack assembly for its mechanical properties, like ability to resist deformation under static loading, vibration, and shock loading. Battery pack enclosure should meet all mechanical properties requirements. In parallel, the battery pack enclosure should be lighter in weight because it will help to improve the vehicle range and increase the battery pack life cycles. In the current study, a design of honeycomb battery pack enclosure is proposed based on mechanical parameters like mass of enclosure, natural frequency, and deformation for generic gravity loading. Baseline battery pack design was validated through physically tested data from literature and further comparative study performed on baseline battery pack enclosure and honeycomb battery pack enclosure for mass, vibrational performance, and static deformation.

INFLUENCE OF PARAMETERS OF OPERATING CONDITIONS OF SELECTIVE LASER MELTING ON SPALL FRACTURE KINETICS OF 12Cr18Ni10Ti STEEL

The results are presented with regard to experimental studies of dynamic strength characteristics of samples made of 12Cr18Ni10Ti steel powder. They were obtained through selective laser melting with various parameters of a technological process at shock-wave compression up to pressures of ~7 GPa. Critical parameters of a process, in addition to powder characteristics, include laser operating conditions: a laser spot diameter, laser power, a laser beam scanning velocity, as well as a powder layer thickness, protective atmosphere, etc. It has been demonstrated that an increase in the scan laser power and a decrease in a powder layer thickness bring about a decrease in a number of internal defects in initial structures of samples. The results are given, which compare strength characteristics of these steels with properties of steel produced by a traditional technique of hot rolling. Shock-wave experiments were carried out using a light gas gun-type facility, which makes it possible to accelerate flat impactors to speeds of ~700 m/s; internal wave processes in samples were reproduced when recording a rate of movement of the sample's free surface via a PDV laser interferometer; a degree of spall fracture was determined by the help of a metallographic analysis of samples recovered in tests. It has been showed that steel samples made through a selective laser melting technique have high spall strength and a lower degree of damage compared to hot-rolled steel under the same conditions of high-speed shock loading. According to the results of the metallographic studies, the presence of internal defects in initial structures of samples associated with a choice of operating conditions of a manufacturing process does not affect a degree of their spall damage. At the same time, a wave pattern of shock wave propagation differs significantly for samples with and without defects.

Influence of microstructure on thermal fatigue effect of laminated tungsten based plasma-facing material

The response of tungsten (W) to thermal shock loading, as the best candidate for plasma-facing material (PFM), is an important issue in the research of future fusion devices. Under thermal loading, thermal irradiation damage, including brittle cracking and fatigue cracking, occurs on the surface of tungsten based plasma-facing material (W-PFM). In this work, a new scheme to suppress the thermal irradiation damage to W-PFM, i.e. the laminated structure W-PFM scheme, is proposed. Thermal fatigue experiments of laminated structure W composed of W foils with different thickness and heat treatment processes are carried out by using an electron beam device. The samples are subjected to thermal pulses with a power density of 48 MW/m<sup>2</sup> for 5000 cycles. The results indicate that the crack damage to the surface of the laminated structure W decreases with the decrease of the thickness of W foils under the same heat treatment conditions. The main cracks are produced on the surface of laminated structure W after cyclic thermal loads have been all approximately parallel to the foil thickness direction. Only the main cracks appear on the surfaces of W foils with a smaller thickness, while crack networks develop on the surfaces of W foils with a larger thickness , in addition to the main cracks with a larger width. In the rolled state, the laminated structure W has the lowest degree of surface plastic deformation for the same thickness. The thermal fatigue crack damage to the surface is quantitatively analyzed by using computer image processing software and analysis software, and scanning electron microscope images of the thermal damage area are finally selected. It is found that the de-stressed state W has the smallest crack area and the smallest number of cracks for the same thickness, indicating that the de-stressed state W has the strongest resistance to irradiation damage. The experimental results also show that in addition to the effect of microstructure, both the uniaxial stress state and the crack-blocking mechanism of the laminated structured W-PFM contribute to the improvement of its thermal fatigue performance.

Superior Protection Conferred by Multi-Layered Graphene–Polyethylene Nanocomposites under Shock Loading

Superior Protection Conferred by Multi-Layered Graphene–Polyethylene Nanocomposites under Shock Loading

Spall strength of additively repaired 304L stainless steel

Additive manufacturing has the potential to repair damaged parts, but the performance of additive materials under high strain rate loading is still uncertain—especially with the added complexity of an interface with an existing wrought material. In this work, 304L stainless steel samples were intentionally damaged and then repaired with wire-fed laser additive manufacturing. The samples were subjected to shock loading to generate incipient spall. Velocimetry and post-mortem metallography results show that when the additive repair process parameters are optimized to reduce porosity and match the equation of state of the original material, the influence of the repair region on the shock propagation is negligible. The free-surface velocity profile and internal damage morphology of the repaired sample are shown to be practically identical to the pristine material.

Application of computer simulation to model transient vibration responses of GPLs reinforced doubly curved concrete panel under instantaneous heating

In this article for the first time, with the aid of computer simulation, transient vibration responses of the concrete doubly curved panel exposed to immediate heating are reported owing to the significance of concrete panels used in civil applications. The substrate includes spring element, shear, torsion, and substrate-structure friction factor. A novel model of a two-parameter substrate is introduced in this research with enough flexibility to involve three forms of polynomial, sinusoidal, and cosinusoidal expansion with various terms in its stiffness. With the aid of Halpin-Tsai micromechanics and the well-known rule of mixtures, the material properties of the graphene nanoplatelet (GPLs) composites reinforced doubly curved concrete panels are modeled. As well as this, for accurate modeling of the current work, the thermal conductivity of each continuous GPLs layer along with thickness direction using mathematical simulation is presented. Finally, entropy, the constitutive heat conduction equation, the Heaviside unit step function, and thermal shock loading are used in the final governing equations. The Laplace transform is employed to solve the temporal variation of the system’s response, while its spatial response is determined with the aid of the harmonic differential quadrature approach (HDQA). For more verification of the current work results and due to the lack of research in the field of the transient response of thermally induced vibrations of the panel, the results of the current work are verified with a Machine learning algorithm. Then, in the results section, some recommendations for enhancing the transient vibrations of the present concrete structure will be thoroughly examined.

Dynamic spall properties of an additively manufactured, high-entropy alloy (CoCrFeMnNi)

The dynamic spall properties of an additively manufactured (AM), CoCrFeMnNi high-entropy alloy (HEA) were investigated as a function of processing defects. Laser Powder Bed Fusion (LPBF) was used to additively manufacture HEA samples that were subsequently subjected to shock loading through plate impact experiments. Seven different combinations of laser power and scan speeds were explored, ranging from 180 to 280 W and 925–1350 mm/s, respectively. All samples were considered within the bounds of lack-of-fusion and keyholing defects based on initial experiments, but exhibited varying degrees of solidification cracking and microstructural changes. Grain size and grain aspect ratio were found to modestly decrease with faster scan speeds and lower laser powers, while cracking associated with the AM process increased with faster scan speeds and higher laser powers. Spall strength and spall damage did not systematically trend with microstructural characteristics such as grain size, but did exhibit a relationship with pre-existing crack density. Spall properties were found to generally degrade with increasing crack density. Evidence of defect compaction was not observed in soft recovered spall samples, thus pre-existing cracks were proposed to degrade spall properties by acting as stress concentrators and preferred damage nucleation sites during tensile impact loading. Here, the presence of manufacturing-related defects, such as cracks, dominated the dynamic response; however, in the absence of these defects, microstructural changes like grain size and texture would be expected to control dynamic behavior.

A coupled phase-field and crystal plasticity model for understanding shock-induced phase transition of iron

In the current work, we propose a chemical-potential-based phase-field model coupled with dynamic crystal plasticity based on a unified energy framework with the aim of understanding the shock-induced α–ϵ–α phase transition (PT) of iron. The plasticity is coupled with the PT through controlling the shear strain energy and the entropy rise during the dynamic deformation. In contrast with previous models, the PT pressure in this model is not a constant but obeys the Gaussian distribution with the applied stress, which is in accordance with the hysteresis effect observed in quasi-static experiments. Moreover, the contribution of multivariants to PT can be distinguished based on reaction-pathway theory. The proposed model quantitatively reproduces the split of the three-wave structure and the “loop” features of the plasticity wave and the phase transition wave, which agree well with the shock loading experiments of polycrystalline and monocrystalline iron, and cannot be well captured by previous models. Furthermore, many new insights in shock wave physics are gained. PT kinetics is found to be influenced by plasticity via the hysteresis effect and the newly generated stress wave induced by the dynamic deformation. First, the rarefaction wave induced by plastic deformation, as well as that by the growth of the child phase, behind the shock front reduces the PT plateau in the wave profile. Second, the plasticity controls the PT driving force and influences the PT hysteresis effect behind the shock front. As yield stress increases, less strain energy is plastically dissipated, and more strain energy drives the PT behind the shock front more efficiently, which results in a sharper slope of the P2 wave.

Application of multi-directional FG material to improve natural frequencies of perovskite solar cells under mechanical shock validated by deep-learning approach

In order to generate electricity from sunlight, spacecraft that operate within the inner solar system often utilize photovoltaic solar panels that are controlled by power electronics. For this purpose, the emerging technologies of perovskite solar cells (PSCs) have attracted plenty of attention recently. Improving the stability of this kind of cell is the main purpose of this research. In the current work, for the first time, dynamic stability analysis of the PSCs, including the multi-directional functionally graded (MD-FG) layer as the host layer, is presented. Also, due to the complex situation of solar cells, this kind of system may be under mechanical shock loading. Various types of PSCs, including cylindrical, spherical, and hyperbolic paraboloid solar cells, by changing curvature factors are modeled. For considering the size-dependency of the PSCs, modified couple stress theory (MCST) with one length scale factor on the strain energy is presented. The forced vibration caused by mechanical shock loading is illustrated by inverting the Laplace transform using the fully modified representation of Abate and Dubner’s solution. A deep neural network (DNN) with independent variables, hidden, input, and output layers, intrinsic neural network parameters, activation function, hidden neurons, and loss function is offered to train the current appropriate structure once the results of mathematical modeling have been obtained. Finally, by applying the two-dimensional differential quadrature method (2D-DQM) as an accurate integral operator, the discretized motion equations can be derived from the weak form of the equations. Finally, in the results section, some suggestion for improving the stability and frequency of the PSCs is discussed.

Start Up And Operation Of A UASB Rector With Molasses As A Preferred Substrate – A Case Study

Anaerobic digestion followed by aerobic treatment has gained wide acceptability for many of the wastewater treatment. Several novel bio-reactors have been developed. All these reactors pose a problem of shock loading, when the high COD organic industrial waste is fed in to the reactor. Further, the normal substrates like glucose, sewage, citric acid may result in addition of a large volume of the substrate solution for a given organic loading. Both these problems are solved by adopting molasses, a typical by-product from the sugar industry. Among the bio-reactors to treat high strength waste waters, the Up-flow Anaerobic Sludge Blanket Reactor (UASBR), has received wide popularity for the treatment of domestic waste waters as well as for a variety of industrial wastewaters. This paper is to present a cogent and a clear picture of the startup and steady state operation of an UASB Reactor with molasses as the initial startup substrate for the development of well settleable sludge granules, the major feature of an UASB Reactor. The UASB reactor was fabricated in transparent Plexiglas. The reactor had a working volume of 9.75 liters with provision of ports for input, output, collection of samples, and collection of gas. Inside the settler, a gas-liquid-solid separation system using a glass funnel and a gas pressurizing plexiglass tube was provided. The aim was to granulate the sludge and acclimatizing it completely to take high organic loading. The feed was supplemented with a fixed COD: N: P ratio by adding urea for nitrogen and KH2PO4 for phosphorous. The HRT was fixed to be 8 hours. The reactor temperature was maintained at 35 ± 20oC. In about 55 days, the buttery seed sludge got granulated at an OLR of 8 g COD/l.day. The SEM of the granules exhibited a mixed morphology on the surface of the granules while filamentous Methanothrix proliferation could be clearly seen in the interior of the granule. Methanoceata and Methanothrix are the two dominant species found in the granules.

Plastic deformation mechanisms and their threshold pressures of Ti6Al4V thin-walled structures induced by laser peen forming

To explore the minimum energy required for laser peen forming (LPF) and broaden the application scope of the process, plastic deformation behaviors of Ti6Al4V thin-walled structures induced by laser shock loading were investigated. LPF experiments varying laser power densities on thin-walled specimens with thicknesses of 0.5 mm and 3.0 mm were conducted. Finite element methods were used to analyze the evolutions of stress and strain with time to understand plastic deformation mechanisms, including the stress gradient mechanism (SGM) and shock bending mechanism (SBM). Experimental results showed that the threshold power density for LPF to deform a 0.5 mm-thick specimen is much lower than to deform a 3.0 mm-thick one. Simulated time/position diagrams of strain reveal that plastic deformation occurs once the shock loading acts on the material in the deformation mechanism of SGM. While in the deformation mechanism of SBM, plastic deformation does not occur until the whole section exhibits an overall bending, which presents an apparent sequential relationship after SGM. Finally, a criterion concerning the threshold pressure and thickness to determine plastic deformation of thin-walled structures under laser shock loading is proposed.

Potential of aerobic granular sludge technology for domestic wastewater treatment of high ammonia from urea fertilizer industry

Fertilizer is the main element that has an essential role in the sector of agriculture. Urea fertilizer has a source of Nitrogen with 46.04%. Ammonia is a chemical complex that is used and produced from the processing of urea fertilizer. A specific domestic wastewater quality standard for industry explains that the maximum level of ammonia allowed in effluent water was 10 mg/l. In the urea fertilizer industry wastewater treatment results were found to be in the range of 19.49 - 42.4 mg/l. Activated sludge technology is considered fairly effective in wastewater treatment but requires a large amount of energy and additional land for handling excess sludge. From the disadvantages, it is necessary to conduct research related to the effectiveness of high ammonia wastewater treatment that is environmentally friendly. Aerobic granule is characterized by a compact and dense structure, high biomass residence time, resistance to shock loading and toxic compounds, and a high settling speed so that it can produce a compact reactor design. Aerobic granule allows ammonia removal to reach more than 97%. This article aims to review the potential of implementing the use of aerobic granular sludge technology for ammonia removal in the wastewater of the urea fertilizer industry.

Laser-driven double shock loading and diagnosis technology for material ejection from surface

The physics of shock-induced ejection is a crucial phenomenon in the field of shock compression science and technology. Limited by loading methods, the previous research primarily focused on the physics of ejecta induced by single shockwave, with few data available on multiple shockwave loading conditions. To solve this problem, we proposed a double shockwave production method based on the high-intensity laser facility, which allows the interval time between the shock waves to be adjusted in the nanosecond to microsecond timescale. Meanwhile, we applied loading techniques to study the ejection behavior of metal tin and integrated photonic doppler velocimetry and high-energy x-ray radiography technology to observe the ejection process. By comparing the experimental results for single and double shockwave, the multiple shock-induced ejection features have been clearly confirmed. Our experimental results provide valuable insight into the behavior of ejecta under multiple shockwave loading conditions, which is of great significance for deepening our understanding of the ejection mechanism.

Dynamic Response of Layered Media to Impact Loading (on the Example of Highways)

Introduction. The main way to assess the load-bearing capacity of road structures (which are layered media consisting of materials of different stiffness) is through impact testing. The analysis of the results of these tests is reduced to the consideration of only peak values of vertical displacements without taking into account the change of these parameters in the frequency and time range. At the same time, it is the study of amplitude-frequency characteristics of displacements that can allow solving a number of urgent problems related, for example, to bringing the actual values of vertical displacements to the values under the design modes of operation of the structure.The purpose of the study is to analyze the dynamic response of layered media (road structures) of automobile roads to impact loading, aimed at bringing the actual parameters of the dynamic response to the design values regulated by the requirements of domestic regulatory documents on road design.Materials and Methods. Modern shock loading facilities allow to reproduce the load with a pulse time of 0.03 s, while the design values of elastic moduli are calculated for 0.1 s. To overcome this contradiction, the authors realized an exact solution of the dynamic Lame equation for a multilayered half-space and constructed a series of amplitude-frequency characteristics of displacements, from the processing of which a simplified functional dependence was derived.Results. The methodology of construction of amplitude-frequency characteristics of displacements on the surface of road pavement under impact impact has been developed, which finds its practical application. On the basis of the exact solution of the dynamic Lame equation by means of statistical processing, a simplified regression dependence for vertical displacements is established. An example of calculation of the elastic moduli of the road structure layers taking into account their reduction depending on the time of load application is presented.Discussion and Conclusion. Within the framework of the study, for the first time, a methodology for bringing the actual values of vertical displacements to the values under the design modes of operation of a road structure, based entirely on the computational analysis of its dynamic VAT, in particular, the amplitude-frequency characteristic of deformation under unsteady impact, has been obtained. The developed approach is able to significantly increase the reliability of diagnostics of highway condition, as well as to ensure the unity of measurements and results obtained during the design and diagnostics of roads.

A theoretical approach for thermomechanical shock analysis of doubly curved panel with respect to geometrical and physical parameters using machine-leaning-based algorithm

In this work, for the first time, bending information of the doubly curved panel under thermo-mechanical shock loading (MSL) with respect to geometrical and physical parameters via both numerically, and machine-leaning-based algorithms is presented. The graphene nanoplatelets composites are used to reinforce the current composite curved panel along with latitudinal direction. It should be note that the current curved panel is reinforced in latitudinal direction with GPLs due to thermo-MSL in the latitudinal direction. The material properties of the current doubly curved structure are obtained with the aid of role of mixture and Halpin–Tsai micromechanics model. As well as this, GPL distribution’s thermal conductivity for each pattern of GPL is considered for high accuracy of the current work’s model. Three-dimension (3D) elasticity theory, linear thermo-elasticity principle, constitutive heat conduction equation, and relaxation time equation are used to present the mathematical modeling of the current work. After obtaining the governing equations, the equations are solved via numerical solution using Chebyshev–Gauss–Lobatto function, and spatial and Laplace latitudinal methods. Deep neural networks (DNNs) as a machine learning method are used to train and test the obtained results from mathematical modeling. After predicting the results, the results are compared with the outcomes of mathematical modeling and show that with the low computational cost of DNNs algorithm, the results can be predicted instead of other high computational cost methods. Finally, some suggestions for improving the thermo-mechanical behavior of the current doubly curved panel under external shock loading.

Tuning dynamic mechanical properties of Cu50Zr50 nanoglasses/ nanopolycrystalline Cu composites investigated by molecular dynamics simulation

Nanoglasses/nanopolycrystalline (NGNP) composites have emerged as a promising approach to balance the strength and plasticity of metallic glasses. Herein, the shock responses of five Cu50Zr50 NGNP composites are investigated via molecular dynamics simulations under a shock velocity of 0.5 to 2.0 km/s. The simulation results reveal that with an increasing fraction of nanocrystalline grains, the Hugoniot pressure, shear stress, and spall strength of the composites are enhanced, while their atomic strain decreases under shock loading. Additionally, due to the dominant structure type changes from an amorphous structure to a crystal structure, the deformation mechanism transforms from the growth of shear transformation zones to dislocation slip, phase transition, and amorphization as the impact velocity increases. In terms of the spallation, the spall strength of the composites rises initially and then declines due to the competing mechanisms of strain rate hardening and shock-induced softening.

Molecular dynamics simulations of several linear homopolymers: Assessment and comparison of shock properties

Understanding the behavior of polymers under shock loading is essential for their applications in car equipment, aircraft, space structure and plastic bonded explosives. Despite much effort, both experimentally and numerically over the last twenty years, there are specificities of the shock behavior of polymers that are still unclear. These include the relation of the shocked state to the dynamic glass transition and the deviation of the Hugoniot locus from the usual linear relation us=c+Sup, with us the shock velocity, c, the bulk sound velocity, up the particle velocity and S an empirical fitting parameter. To address these questions this work studies direct shock simulations in molecular dynamics (MD) of three different polymers, cis-1,4-polybutadiene, polystyrene and phenoxy resin. After thoroughly assessing that the polymer configurations created in this work are correct with respect to mass density, structure factor, chain dimensions and Hugoniot locus, this work focuses on two aspects of the behavior under shock loading. (i) The deviation of the Hugoniot locus from the linear relation us=c+Sup is related to a change in the relative contribution to the shock energy of the bonding and non-bonding potential energies as the shock strength increases. (ii) The shear stress relaxations behind the shock front are compared for the three polymers. It is found that the polymers with the highest glass transition temperature have the most slowly relaxing shear stress behind the shock front.