Zhiliang Wang^1,*, Nuocheng Tian², Jianguo Wang³, Shengqi Yang³, Guang Liu¹

CMC-Computers, Materials & Continua, Vol.59, No.1, pp. 275-296, 2019, DOI:10.32604/cmc.2019.04247

Abstract The mechanical behaviors and energy dissipation characteristics of heat-treated granite were investigated under repeated impact loading. The granite samples were firstly heat-treated at the temperature of 20°C, 200°C, 400°C, and 600°C, respectively. The thermal damage characteristics of these samples were then observed and measured before impact tests. Dynamic impact compression tests finally were carried out using a modified split-Hopkinson pressure bar under three impact velocities of 12 m/s, 15 m/s, and 18 m/s. These test results show that the mineral composition and the main oxides of the granite do not change with these treatment temperatures. The number of microcracks and… More >

Liwei Wu¹, Dan Huang^1,*, Yepeng Xu¹, Lei Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 561-581, 2019, DOI:10.31614/cmes.2019.04347

Abstract Strain hardening and strain rate play an important role in dynamic deformation and failure problems such as high-velocity impact cases. In this paper, a non-ordinary state-based peridynamic model for failure and damage of concrete materials subjected to impacting condition is proposed, taking the advantages of both damage model and non-local peridynamic method. The Holmquist-Johnson-Cook (HJC) model describing the mechanical character and damage of concrete materials under large strain, high strain rate and high hydrostatic pressure was reformulated in the framework of non-ordinary state-based peridynamic theory, and the corresponding numerical approach was developed. The proposed model and numerical approach were validated… More >

Shenbo Li^1,*, Qi Tong¹, Chaozhe Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.2, pp. 425-446, 2019, DOI:10.31614/cmes.2019.03936

Abstract As the platform for surface-source infrared decoys, the target aircraft is the aim of attacks in air-to-air combat. It can quickly and accurately evaluate the jamming effectiveness of the surface-source IR decoy in various states of motion is important for enhancing the security of the aircraft. This paper proposes a model of surface-source IR decoy, and compares and analyzes simulated and measured infrared images of diffusion. A system to assess the effectiveness of the jamming of the surface-source IR decoy, target aircraft, and infrared guided missile called “Trinity” is established. Simulations were conducted to assess the impact of flight height,… More >

Zhijie Huang^1,2,3, Zuyu Chen^1,2,3, Xiaodan Ren^4,*, Jing Hu³, Xuedong Zhang³, Lu Hai⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.1, pp. 139-155, 2019, DOI:10.31614/cmes.2019.04596

Abstract Damage and threats to hydraulic and submarine structures by underwater explosions (UNDEXs) have raised much attention. The centrifuge model test, compared to prototype test, is a more promising way to examine the problem while reducing cost and satisfying the similitude requirements of both Mach and Froude numbers simultaneously. This study used a systematic approach employing centrifuge model tests and numerical simulations to investigate the effects of UNDEXs on an air-backed steel plate. Nineteen methodical centrifuge tests of UNDEXs were conducted. The shock wave pressure, bubble oscillation pressure, acceleration and the strain of the air-backed steel plate were recorded and compared… More >

C. Frueh¹

CMES-Computer Modeling in Engineering & Sciences, Vol.111, No.2, pp. 171-201, 2016, DOI:10.3970/cmes.2016.111.171

Abstract In recent years, probabilistic tracking methods have been becoming increasingly popular for solving the multi-target tracking problem in Space Situational Awareness (SSA). Bayesian frameworks have been used to describe the objects' of interest states and cardinality as point processes. The inputs of the Bayesian framework filters are a probabilistic description of the scene at hand, the probability of clutter during the observation, the probability of detection of the objects, the probability of object survival and birth rates, and in the state update, the measurement uncertainty and process noise for the propagation. However, in the filter derivation, the assumptions of Poisson… More >

S. Freire¹, D. Ehrlich¹, S. Ferri¹

CMES-Computer Modeling in Engineering & Sciences, Vol.109-110, No.2, pp. 159-182, 2015, DOI:10.3970/cmes.2015.109.159

Abstract Media and specialized scientific literature are often addressing the “increasing impact and ensuing damages due to natural hazards”. It is frequently argued that a rising frequency and intensity of hazards is responsible for the increase in losses. The role of increasing population exposure due to phenomenal population growth, or urbanization as a driver of risk is still insufficiently addressed. We investigate spatio-temporal changes in population exposure to seismic hazard and their role on impacts from earthquakes in the XX century. Spatial analysis is used to study historical population distributions in relation to seismic intensity, at the global and continental levels.… More >

Riitta Molarius¹, Pekka Tuomaala¹, Kalevi Piira¹, Minna Räikkönen¹, Christoph Aubrecht², Maria Polese³, Giulio Zuccaro^3,4, KaroliinaPilli-Sihvola⁵, Kalev Ranna

CMES-Computer Modeling in Engineering & Sciences, Vol.109-110, No.2, pp. 131-158, 2015, DOI:10.3970/cmes.2015.109.131

Abstract In northern regions, society can be seriously interrupted by a prolonged electricity network blackout due to a winter storm that cuts off power, communication and road networks. Due to hard winter weather it is essential to enhance the resilience of society to avoid danger to life. This can be achieved by developing new models to enhance preparedness for coming disaster events and to support rescue and other authorities to focus their resources on the most vulnerable targets in actual cases of emergencies. This paper presents a part of the results of activities performed within the EU project ‘CRISMA – Modelling… More >

Chu Wang, Lucy T. Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.1, pp. 41-67, 2014, DOI:10.3970/cmes.2014.098.041

Abstract Bloodstain pattern analysis (BPA) in forensic science is an important tool to solve crime scenes. The complex dynamic behavior of blood drops poses great challenges for accurate fluid dynamic simulations. In this paper, we specifically focus on simulations of blood drop spreading and impact, which may involve contact line hysteresis and spattering of drops as they interact with solid surfaces. Here, we set up a numerical framework that combines (1) the connectivity-free front tracking (CFFT) method for modeling multiphase (air and liquid) flows and (2) a dynamic contact line model for modeling fluid-solid contact line. Both components are necessary in… More >

H.T. Zhu ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.97, No.3, pp. 281-298, 2014, DOI:10.3970/cmes.2014.097.281

Abstract This study is concerned with a solution procedure to obtain the probability density function (PDF) of a vibro-impact Duffing oscillator under fully correlated external and parametric Gaussian white noises. The proposed solution procedure consists of three steps. In the first step, the Zhuravlev non-smooth coordinate transformation is adopted to introduce an additional impulsive damping term, in which the original vibro-impact oscillator is converted into a new oscillator without any barrier. After that, the PDF of the new oscillator is obtained by solving the Fokker-Planck equation with the exponential-polynomial closure method. Last, the PDF of the original oscillator is formulated in… More >

Smitha Gopinath¹, C.K. Madheswaran¹, A. Rama Ch,ra Murthy¹, Nagesh. R. Iyer², Barkavi.T³

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.2, pp. 151-172, 2013, DOI:10.3970/cmes.2013.092.151

Abstract This paper presents the details of experimental and numerical investigations performed on fabric reinforced concrete (FABcrete) panels under impact loading. Experimental investigations have been carried out using drop weight impact on a square FABcrete panel to study the damage, failure mode and acceleration. The drop weight of 20 kg is used for the study and drop heights have been varied as 100mm, 200mm and 300mm. Numerical simulation of the drop weight impact tests on FABcrete panels have been carried out and observed that there is a good correlation between experimental and numerical predictions. It is observed that the FABcrete specimen… More >