bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on optimization of warehouse layout based on SLP theory-- Take Deppon Express Warehouse for example
Authors: Le Xiaobing , Wang Xueliang , Huang Zhiheng
Published: September 2021

This paper takes Deppon Express Company as an example to study the optimization of the layout of the store warehouse under the standardized operation mode. First of all, it Analyzes warehouse layout present situation of the express company, and gets the problems of the warehouse layout of the company, for example, the layout of the lack of scientific, as well as part of the operational areas of position arrangement is not reasonable and unreasonable action path which leads to the whole business operation efficiency is low. Finally, thus using SLP to solve those problems, and put forward the company store aisle warehouse layout optimization strategy of management according to the comprehensive relations preliminary to the data warehouse layout optimization figure.
Problems and Development Suggestions in Automobile Supply Chain Finance
Authors: Yan Kong , Yanna Wang
Published: September 2021

With the rapid development of domestic automobile consumption, the financing problem of upstream and downstream enterprises in the automobile industry has become the focus of the industry. As an innovative financial tool, automotive supply chain finance provides a solution for small and medium-sized enterprises in the industrial chain. From the perspective of the automotive industry chain, this paper analyzes the supply side and demand side of the capital, summarizes the problems existing in the automotive supply chain finance, and finally puts forward solutions from the aspects of the industry side and the technology side to provide suggestions for the development of the industry.
A Study on the Co-Agglomeration of Manufacturing Industry and Producer Services in Heilongjiang Province
Authors: Dong Hongmei , Huang Lili
Published: September 2021

Manufacturing industry and producer services are two important categories of industrial development in Heilongjiang Province. The co-agglomeration development is conducive to improving the interaction level between them and promoting the development of regional industrial cluster. Based on the relevant data of manufacturing and producer services in Heilongjiang Province, this paper uses the location quotient model to estimate the co-agglomeration of manufacturing and producer services. Heilongjiang Province should promote the integrated development of producer services and manufacturing industry, so as to realize the transformation and upgrading of traditional manufacturing industry in the old industrial base.
Empirical Study on the Degree of Coupling Coordination Between Ice-snow Tourism and Cultural Industry Integration ——Take Harbin as An Example
Authors: Xiaofeng Zhang , Shiyu Lu
Published: September 2021

Harbin is the capital of Heilongjiang Province in China, the ice-snow tourism industry develops rapidly. How to integrate with the cultural industry and cultivate a new growth point of Harbin is a hot research area. Harbin culture and tourism industry has a good foundation, the development of industry integration accelerates and infrastructure is increasingly perfect. However, it also faces some practical problems, such as the lack of the depth of industrial resources exploitation and utilization efficiency, the low integration degree of ice-snow tourism and cultural industry chain, and the lack of cultural products of high-end music and painting leisure tourism. Build a coupling and coordination model and have a empirical analysis of the degree of coupling coordination between Harbin's ice-snow tourism and cultural industry integration, the conclusion is that the coupling coordination is low and the development of cultural industry lags behind.
Research on the Optimization and Upgrading of Rural Tourism Economy Industry
Authors: Dong Hao
Published: September 2021

With the rapid development of China’s economy and the increase of people’s material and cultural needs, the current tourism industry has received people’s love. The tourism industry has become an essential way for many people to enjoy leisure and entertainment. The traditional tourism model can no longer meet the current needs of different consumer groups. Rural tourism is more and more admired by people. The rural tourism economy has become an important industry driving local economic growth. This article analyzes the rural tourism market and finds out the problems in the rural tourism industry. This article analysis the problems existing in the rural tourism industry, and provide more paths for optimizing the rural tourism economic industry under the background of China’s rural revitalization.
Discussion on Disaster Education and Prevention Strategies Based on SPSS Analysis - Taking disaster prevention research of Chengdu as an example
Authors: Yanghui Li
Published: September 2021

Post-disaster prevention strategies and education affect and shape the future development pattern and behavior of disaster prevention and reduction. Chengdu has made great achievements in disaster prevention education after the Wenchuan earthquake. Data from several dimensions has been analyzed through SPSS to explore the reasons for its success. The first dimension is disaster prevention education, including disaster research, disaster educational institution bases and disaster prevention education halls, etc. The second one is legal strategies for disasters, including current disaster-related policies and regulations of Chengdu. The disaster education in Chengdu over the ten years has been reviewed based on the weighted processing of historical data by SPSS. Though achievements have been made, there is room for improvement in the cultivation of a legal cultural concept for disasters and the establishment of a disaster accountability mechanism. Therefore, this paper reviewed the past legal education experience of Chengdu and made targeted suggestions based on the discrete processing analysis of multiple factors of post-disaster education so as to provide more thoughts on future disaster prevention strategies and legal education for disasters.
Demand and Supply Docking Mechanism of Language Service Talents for Foreign Tourism Industry of China
Authors: Qian-qian Lei , Hai-yang Liu
Published: September 2021

Data of foreign tourism industry of China in recent years is analyzed and a demand-and-supply docking model is created based on a deep research of the contradictions between the supply and demand of language service talents in China’s foreign tourism industry. On the whole, the demand for language service talents is in urgent with the foreign tourism market’s high-speed expansion; the demand for multi-lingual language talents in the foreign tourism industry of China has been increasing, including the talents of Chinese itself as a foreign language; and the talents with combined skills of Language + Tourism + X or Tourism + Language + X are in short. In order to meet the demand of foreign tourism market of China for language service talents, the supply-and-demand mechanism should be firstly clarified and then integrate the following docking paths between the language talent’s supply and demand. Firstly, the government should offer its policy support and make an overall planning for the cultivation of language service talents; secondly, colleges and universities at different levels should be demand-oriented to strengthen the cultivation of different types of language service talents; thirdly, foreign tourism industry and its industrial enterprises should strengthen their own ability of language talent cultivation and also their ability of serving colleges and universities supplying language talents. It is necessary to establish a Cooperation Steering Committee of industry, universities and colleges, research centers, enterprise, and the government, so as to realize the seamless connection between the talent cultivation of colleges and universities and the talent demand of enterprises.
Systematic Research on Supporting the Development of Information Technology Sports Industry Based on Big Data
Authors: wei Li Zhao , nan Li Ya
Published: September 2021

Today’s rapid development of computer information technology has driven the progress of its related technologies and industries. In order to develop the sports industry more conveniently, make it more intelligent and better serve mankind, people have gradually increased their attention to the development of the sports industry. The report of the Nineteenth National Congress of the Communist Party of China pointed out that in the future, the strategy of “Healthy China” will be implemented. As an important part of the consumption of “Healthy China” and modern life, the sports industry will benefit from many aspects such as national policies, market demand and industrial restructuring. However, with the rapid economic and social development and the overall progress of people’s lives, the demands in all aspects are constantly improving. The purpose of this article is to study the system that supports the development of the information technology sports industry based on big data. This paper discusses the concept, structure, function, elements and characteristics of the development system of our country’s sports industry based on the theory of system science. Based on the theory of system science, this article discusses the concept, structure, function, elements and characteristics of the development system of my country’s sports industry. Analyzed the development status of my country’s sports industry; systematically analyzed the advantages and disadvantages of information technology to support the development of the sports industry, and on this basis, proposed the strategic choice of information technology to support the development of the sports industry in the current environment. This paper conducts experimental research through questionnaire surveys, analyzes the composition of the sports market, the characteristics of sports consumption, influencing factors and sports property rights, and summarizes the development models, characteristics and enlightenments of the foreign sports industry. The experimental research results show that the data collection function of the sports industry development system C accounted for the highest proportion and the correctness test was the most accurate, 41.43% and 37.12%, respectively. The index feasibility function was System A, accounting for 38.07%. Both A and System C are around 35%, and System B is the lowest, only 29.65%. All in all, System C is a good reference system with outstanding functions in all aspects.
Research on the Equalization Level of Basic Public Services in Heilongjiang Province
Authors: Zhang Xiaofeng , Yang Shumin
Published: September 2021

As an important link in the development of urban-rural integration, equalization of basic public services in urban and rural areas is the foundation of urban-rural integration and an important aspect of improving the quality of life of urban and rural residents. To understand the level of equalization of basic public services in urban and rural areas, it is necessary to reasonably measure the level of equalization of basic public services. This article constructs an evaluation system for the equalization of basic public services in urban and rural areas from the four dimensions of public education, social security, medical and health, and infrastructure. The entropy method is used to obtain the equalization index of basic public services in Heilongjiang Province. On this basis, a comprehensive analysis of the equalization of basic public services in the integrated development of urban and rural areas is carried out and corresponding policy recommendations are put forward.
Research on the Innovative Development of Martial Arts Tourism Economy in Hubei Province under Internet+ Mode
Authors: Ke Yi
Published: September 2021

Sports tourism is generally regarded as a new growth point for economic development, and is gradually becoming a new way of life and leisure for people. Although Hubei is a province with rich tourism resources and a long history of martial arts, the pace of development of martial arts tourism industry as a whole is rather slow. Through the methods of literature and field research, the author has studied the martial arts tourism industry in Hubei Province and has proposed development strategies and approaches from the perspective of Internet+, emphasizing the need for innovative thinking and initiatives to promote the development of the martial arts tourism economy in Hubei Province.
The Construction of Exclusive Agricultural E-Commerce Platform of Hubei Province Focuses on the Development of “Agriculture, Rural and Farmers”
Authors: Liu Quanhong , Li Yufan , Gao Xiang
Published: September 2021

The production and marketing of agricultural products has always been bothering the government for a long time, and “” building an exclusive agricultural e-commerce platform in Hubei may be a good way to solve the unsalable problem of agricultural products and promote the sustainable development of “agriculture, rural and farmers”. Thus, this paper discusses the necessity and advantages of building an exclusive agricultural e-commerce platform in Hubei Province, we found that the agriculture-related e-commerce has problems in the aspects of logistics, brand establishment and customer loyalty. Accordingly, this paper puts forward some countermeasures for the functional settings and operation strategies of the exclusive agricultural e-commerce platform in Hubei Province.
Literature Review on the Development of Public-Private-Partnership Leisure Sightseeing Agriculture
Authors: Wu Yuexia , Wang Xiuping
Published: September 2021

Comprehensive use of content analysis method and quantitative visualization analysis method, taking journal papers and master's thesis in the field of PPP of CNKI database as samples, through content analysis of research topics, research nature, and analysis of authors, literature discipline distribution, research hotspots and other fields, To discuss the trend characteristics of research and development in the field of PPP leisure agriculture in my country.
Effect of moxifloxacin on pharmacokinetics of enalapril in rats
Authors: Jing Zhao , Jiarui Peng , Yinxia Zhang
Published: September 2021

The purpose of this study was to investigate the effect of moxifloxacin on the pharmacokinetics of enalapril. Single administration experiment: 12 Wistar rats were randomly divided into two groups on average. Control group: enalapril (15mg/kg)+ normal saline combined group: enalapril (15mg/kg)+ moxifloxacin (80mg/kg), intragastric administration. Blood samples were measured by LC-MS/MS. Multiple administration experiment: 12 Wistar rats were randomly divided into two groups on average. The control group was given normal saline (day1-7)+ enalapril (day8,15mg/kg), and the combination group was given moxifloxacin (day1-7, 80mg/kg)+ enalapril (day8,15mg/kg) by intra-gastric administration. The treatments were the same as above. Pharmacokinetics parameters were calculated using Winnonlin 6.1 software and the two groups were compared using SPSS18.0 software. In single administration experiment compared with the control group, the AUC(0-t) and Cmax of enalapril were decreased by 31.99%（P<0.05), 42.57% (P<0.05) in the combined administration group. Quinolone antibiotics and ACEI drugs should not be taken at the same time during clinical treatment to avoid drug interactions that may occur when combined drugs are used.
Relationships between SHANK3 and Autism Spectrum Disorder
Authors: Liu Zikuan
Published: September 2021

Autism Spectrum Disorder is a term that is used to describe people who have difficulties communicating with others and limited actions repetitive actions. Autism could be caused by both genetic and environmental conditions, and the Shank3 gene in the Shank family is one of the high-risk genes that has been found as one of the factors. However, although a lot of researches have been done to find out the relationships between Shank3 and autism, it is known by only a few people. This article will briefly talk about autism and Shank3 and review how Shank3 mutation causes autism and the changes in the brain and behaviour.
COVID-19 Vaccine Comparison: How to Choose the Best Suiting Vaccine for Different Needs
Authors: Liu Chuyao , Lu Aiyun , Wu Xiaoyu
Published: September 2021

Varied measurements have been developed to solve the COVID-19 pandemic, and one of the best ways is vaccines. This paper aims to compare different kinds of vaccines and help people or countries to choose the best suitable vaccine needs based on their different needs. It provides a broader and more detailed analysis of variant vaccines on different levels. In the sequence of technology maturity, inactivated vaccines including CoronaVac, BBIBP-CorV vaccine, and WIBP-CorV vaccine, viral-based vector vaccines including AstraZeneca COVID-19 vaccine and Johnson & Johnson’s COVID-19 vaccine, and mRNA vaccines including Moderna vaccine and Pfizer/BioNTech vaccine have been discussed. There are several important elements of these vaccines, for example, mechanism, effectiveness, and side effects. Different criteria make comparison. For effectiveness, in general, Moderna and Pfizer/BioNTech vaccines could be a better choice. For cost-performance ratio, the AstraZeneca COVID-19 vaccine is the best. As for inoculators’ age and race, old people are suggested to take CoronaVac, and Pfizer/BioNTech vaccine and CoronaVac are suitable for all races. In terms of mutant variant distribution, CoronaVac could be the best choice. Based on safety concerns, inactivated vaccines are better choices. For the developing period, mRNA vaccines win the game. In conclusion, this paper provides further directions for countries seeking the best suitable vaccine for their citizens. After comparing the main vaccines available, we provide a clear view of when countries decide. There would be specific vaccines best suiting specific needs of inoculators and countries.
Lessons learned from China’s mitigation strategies in fighting COVID-19
Authors: Liu Sijiang , Wan Mingyuan
Published: September 2021

In late 2019, the first SARS-CoV-2 case was reported in Wuhan, China. It has been known as a deadly virus that could cause many severe health complications, particularly respiratory illnesses. With its extraordinary ability to transmit between humans, the coronavirus disease 2019 (COVID-19) has spread worldwide, including Antarctica and the Arctic region. On 11th March 2020, the World Health Organization (WHO) declared the COVID-19 as a public health emergency worldwide (global pandemic) to raise global awareness of the dangerous virus. With immediate and efficient public health interventions, progress has been seen in many countries such as China and New Zealand. Therefore, in this review, we summarized the important public health risk mitigation measures applied in China.
Progress in tumor-derived exosome miRNA regulating tumor metastasis research
Authors: Du Shuanglong , Li Yuqing
Published: September 2021

Tumor metastasis is the most important biological feature of a malignant tumor. It is also a complex process involving multi-step, multi-gene, and multi-products. Tumor cell-derived exosomes are vesicles secreted by tumor cells, containing proteins, lipids, noncoding RNA, and other components. MicroRNA (miRNA) of tumor cell-derived exosomes affects the tumor cell microenvironment and participates in tumor metastasis by activating various signaling pathways. Here, we summarize the miRNA and its related pathways that affect many factors of tumor metastasis and discuss the role of tumor-derived miRNA in the treatment and prevention of tumor metastasis. We also conclude the targets of tumor-derived miRNA in recent years. This article can provide new ideas for the development of tumor metastasis targeting drugs in the future.
Initial Characterization and Expression Pattern Analysis of Tobacco (Nicotiana Tabacum) HMGS Gene
Authors: Zhao Meiwei , Zhang Tao , Yang Lei , Feng Hongtao , Zhao Zhengxiong
Published: September 2021

3-hydroxy-3-methylglutaryl coenzyme A synthase (HMGS) is a member of condensing enzymes that catalyze a Claisen-like condensation reaction.The tobacco (nicotiana tabacum) HMGS gene was firstly characterized using the rapid amplification of cDNA ends methods based on one tobacco EST. The full-length tobacco HMGS gene mRNA was 1,773bp containing a 1389 bp open reading frame, which encodes a protein of 462 amino acids. Sequence analysis revealed that the HMGS of tobacco shares high homology with the HMGS of nicotiana tomentosiformis (96%), nicotiana attenuata (95%), Nicotiana sylvestris (95%), nicotiana benthamiana(94%), solanum lycopersicum(94%), solanum tuberosum(93%) and withania somnifera(93%). Results also showed that tobacco HMGS gene has a closer genetic relationship with the HMGS gene of withania somnifera. Tissue expression profile analysis revealed that the tobacco HMGS gene was highly expressed in flower, but moderately expressed in leaf and stem, and weakly expressed in root. Our experiment established the foundation for further research on this tobacco gene.
Smoking Products Suppress Type I IFN During SARS-Cov-2 Infection
Authors: Lu Zhenni
Published: September 2021

Coronavirus disease 2019 (COVID-19) is a global pandemic caused by the severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), which can lead to the development severe pneumonia. While some hospital data shows a positive correlation between smoking and severe pneumonia, more molecular-level mechanisms need to be determined. The previous study investigates the mechanism of the negative effect of smoking on anti-viral infection on Type I interferons (IFNs). Research has shown that Type I IFNs play an important role in defending against SARS-Cov-2. Here, we want to investigate smoking components’ effects on SARS-CoV-2 at the molecular level in vitro and give some ideas on the correlation between smoking and syndrome.
Initial Characterization and Expression Pattern Analysis of Tobacco (Nicotiana Tabacum) 2-Hydroxyisoflavanone Dehydratasedase Gene
Authors: Zhao Meiwei , Miao Song , Guo Jun , Li Yongyu , Zhao Zhengxiong
Published: September 2021

The complete mRNA sequence of one tobacco (nicotiana tabacum) gene—2-hydroxyisoflavanone dehydratasedase, was amplified using the rapid amplification of cDNA ends methods based on one tobacco EST. The full-length tobacco 2-hydroxyisoflavanone dehydratasedase gene mRNA was 1,278bp containing a 966 bp open reading frame, which encodes a protein of 321 amino acids. Sequence analysis revealed that the 2-hydroxyisoflavanone dehydratasedase of tobacco shares high homology with the 2-hydroxyisoflavanone dehydratasedase of nicotiana tomentosiformis(99%), capsicum annuum(78%), potato(75%), lycopersicon pennellii(73%) and lycopersicon esculentum(72%). BLAST analysis within the tobacco high throughout genomic sequences database revealed that this gene has no intron and is a single exon gene. Results also showed that tobacco 2-hydroxyisoflavanone dehydratasedase gene has a closer genetic relationship with the 2-hydroxyisoflavanone dehydratasedase gene of nicotiana tomentosiformis. Tissue expression profile analysis revealed that the tobacco 2-hydroxyisoflavanone dehydratasedase gene was highly expressed in leaf and flower, but moderately expressed in root and stem. Our experiment established the foundation for further research on this tobacco gene.
A review of COVID-19: A summary of the epidemic in Wuhan and other local areas in China
Authors: Hu Kaiyin , Su Yichao , Wang Jiaqi , Xu Yuzhe
Published: September 2021

COVID-19 is a new kind of coronavirus that was found in 2019 and it has swept the world until now. Reviewing it and discovering the problem is what we must do. In this scenario, the influence of COVID-19 on the world, and especially in China since it is the country where COVID-19 first outbreak, has been thoroughly reviewed. The main point of this paper is to identify the epidemiological information of COVID-19 and to review typical cities that are most influenced by COVID-19, such as Wuhan, Dalian, and Shijiazhuang. Moreover, discovering and comparing the characteristics and regulations according to different periods have also been carefully performed. With the understanding of the infection of COVID-19, the bright future in which prevention and control measures of nosocomial infection are improved is surely within reach. Furthermore, the psychological construction and management in fundamental systems require more attention.
Effects of strain rate and bond preparation for dissimilar materials in energy dispersive applications
Authors: Commins Tom , Siviour Clive R
Published: September 2021

Composite materials, typically consisting of two or more dissimilar materials adhered together in layers, are frequently used for energy absorption applications. The interface and material characteristics strongly influence the global energy absorptive capability of the composite. This research focuses on ceramic-polymer interfaces and, in particular, links between the properties of the composite, the interface and the separate materials. After characterisation of the materials, the effects of impact speed and bond condition were considered for a polymer-ceramic bond in a threepoint bend configuration. Specimens were loaded in a screw-driven machine at 0.05 mm s-1 and through projectile impact at speeds of approximately 50 m s-1. Screw-driven experiments were performed at ambient and sub ambient conditions, with the temperature chosen to simulate the expected polymer performance in the gas gun experiment, making use of the equivalence of rate and temperature for polymers.
Soft projectile impact forces measurement using Hopkinson bars: application to ice, artificial bird and rubber
Authors: del Cuvillo Ramón , Artero-Guerrero Jose Alfonso , Pernas-Sánchez Jesús , López Puente Jorge
Published: September 2021

This work presents an experimental campaign of impacts of soft projectiles to measure the induced force during the impact. Three different materials acting as soft impactors that could strike against a aeronautical structural component: ice, artificial bird and rubber have been impacted at several velocities against an aluminium Hopkinson bar. This device has been instrumented with semiconductor strain gauges that allow to obtain the induced compression strain. Additionally, all the impacts were recorded using high-speed video cameras, allowing the kinematic analysis of the projectile during the impact. After the results study, it has been concluded that there is a linear dependency between the kinetic energy and the peak force for all three materials. Added to that, it has been proved that the higher peak force corresponds to ice, despite the kinetic energy, followed by rubber and finally the artificial bird. In addition, while ice and artificial bird projectiles get radially dispersed after the impact, rubber spheres rebound due to its different behaviour. The obtained data is of great interest to design structures which could be subjected to impacts of soft materials such as aeronautic structures
Design and Simulation of Insert to Measure Dynamic Sliding Friction in a Split-Hopkinson Pressure Bar
Authors: Euser Virginia , Goodbody Austin , Yablinsky Clarissa , Denissen Nicholas , Morrow Benjamin
Published: September 2021

Interfacial friction is a key aspect to understanding and modelling dynamic processes in which materials interact. However, friction is a complex phenomenon that depends on a multitude of factors, including sliding velocity. Understanding how friction behavior changes as a function of sliding rate is thus crucial for accurately simulating dynamic processes. Recent literature has shown that the split-Hopkinson pressure bar can be adapted for friction measurements associated with high sliding rates. The present work introduces an insert designed to be transferrable between a quasi-static load frame and a compression split-Hopkinson bar, enabling friction measurements across a wide range of sliding velocities (10-4 – 20 m/s). Here, the split-Hopkinson pressure bar setup is modelled using a multiphysics research code (FLAG), developed at Los Alamos National Laboratory (LANL), to identify and reduce potential issues in the configuration prior to experimental implementation.
The split Hopkinson bar bulge setup: a novel dynamic biaxial test method
Authors: Corallo Luca , Verleysen Patricia
Published: September 2021

In sheet metal forming, very often, large plastic deformations are imposed to a thin plate. An accurate description of the material’s elastoplastic response is therefore of paramount importance to perform finite element (FE) simulations of an actual forming operation. Reliable stressstrain data till significantly larger strains compared to tensile tests can be identified by means of bulge test. In this work, a dynamic hydraulic bulge test is proposed. The novel split Hopkinson bar bulge setup, combines features of classical split Hopkinson pressure bar (SHPB) and hydraulic bulge tests. The special configuration of the Hopkinson bars leaves the sample surface fully accessible. As such, high-speed optical measurements can be performed on the sample surface allowing the application of, for instance, digital image correlation (DIC) for full-field displacement strain mapping. The potential of the facility is explored by performing experiments on 0.8mm thick Al2024-T3 sheet.
Multi-instrumented dynamic loading experiments on laminated glass
Authors: Le Gourriérec Corentin , Durand Bastien , Roux Stéphane , Brajer Xavier , Voillot Benoît , Villey Richard
Published: September 2021

Describing quantitatively the response of laminated glass to low-velocity (~5 m/s) impacts by rigid bodies is an important issue because of its significance in terms of structural degradation and integrity, key parameters for people safety and anti-intrusion performances. This study aims to address the formation of cracks during graveling and steel ball drop tests, so, two well-instrumented experimental set-ups are proposed to study cracking in reproducible conditions. The first device can be seen as a mini-Hopkinson bar system, which from two strain gauges, allows to estimate force and velocity at a sharp indent tip. The second device, reproducing a blunt impact, exploits stereo-Digital Image Correlation (D.I.C.) measurements of the laminated glass surface.
Analysis of high velocity impacts of quasibrittle material fragments with a Hopkinson bar
Authors: Rodríguez-Sereno J. M. , Pernas-Sánchez J. , Artero-Guerrero J.A. , López Puente J.
Published: September 2021

In this work it has been characterized the impact behaviour of quasibrittle fragments against a Hopkinson bar in a wide range of impact velocities (70-180 m/s). Hopkinson bar is designed to measure the impact forces thanks to a proper instrumentation. In this case, semiconductor strain gauges, which sensibility is higher than common strain gauges, are used. Two material are studied to widen the range of applicability of the experimental facility: PMMA and a woven composite material. Moreover, two high speed cameras (Photron SA-Z) have been used to obtain the displacement and strain field of the fragment impactor using 3D Digital Image Correlation (DIC). A special technique has been used to print the speckle in the fragment based on previous works. The developed experimental methodology has shown the different failure modes that may happen in the fracture process when the quasibrittle fragments acts as the impactor providing a better understanding of its physical behaviour.
Analysis of dynamic fracture properties of High-Performance
Authors: Rey-de-Pedraza Victor , Cendón David , Sancho Rafael , Gálvez Francisco
Published: September 2021

Concrete product research has experimented a deep change during the last decades in the search of novel products with improved mechanical properties. Conventional concrete (CC) is now being replaced by new high-performance-concrete (HPC) mixes, with compressive strengths ranging from to 80 to 200 MPa, offering great chemical resistance and improved durability. The use of these HPC mixes has been extended to a wide diversity of applications, from civil to military structures, allowing the development of new designs by increasing the compressive properties with a notorious self-weight decrease. As opposite to the improved quasistatic behaviour, HPC may be more susceptible to certain dynamic actions as compared to conventional mixes. Research in the dynamic behaviour of these new mixes is needed in order to ensure resilient structural designs. In the present paper, a compared analysis of the dynamic response of HPC mixes versus conventional concrete is carried. Using a Modified Hopkinson Bar, spalling tests are performed over cylindrical concrete specimens. Results on the dynamic tensile strength are compared for CC and HPC.
Strain-rate dependency of bio-based cellular materials under a large range of temperature
Authors: Le Barbenchon Louise , Viot Philippe , Girardot Jérémie , Kopp Jean-Benoît
Published: September 2021

Polymeric cellular materials are used in many different application domains such as transport, sport, food, health and energy. Therefore, the conditions of use of these materials represent wide temperature and strain-rate ranges. The mechanical behaviour of these foams demonstrate a strong dependency to it. In order to be able to predict such dependency, its origin has to be better understood. For this study, a bio-based cellular material, agglomerated cork, has been chosen to evaluate the temperature and strain-rate dependency of the mechanical behaviour. The visco-elastic behaviour of the material was first studied between −80°C and 100°C at frequencies between 0.01 Hz and 100 Hz. The compressive mechanical behaviour was then studied on a large range of temperature (from −30°C to 100°C) and strain rates (from 4.2 10−5 s−1 to 1250 s−1). A specific set-up was finally used to operate dynamic tests at low and high temperature. These results were used to discuss the evolution of the mechanical beahviour with these environnemental conditions based on the knowledge of the mechanical behaviour of the constitutive materials.
High-fidelity damage modelling of CFRP laminates for impact and crashworthiness applications – dynamic tube crushing simulations
Authors: Sommer D. E. , Thomson D. , Falcó O. , Quino G. , Cui H. , Petrinic N.
Published: September 2021

Drop weight impact experiments were conducted on angle-ply carbon fibre reinforced polymer (CFRP) composite crush tubes. The dynamic response was modelled using explicit finite element methods and continuum damage mechanics and cohesive zone modelling in both Abaqus/Explicit and LS-DYNA. User-defined constitutive models for the intra-ply behaviour were used and a fibre-aligned meshing technique was implemented. The results of the experiments and simulations are compared to evaluate accuracy of the different modelling techniques, highlighting the advantages and drawbacks of each approach. Among these, the choice of meshing strategy is shown to be especially important in capturing the physical propagation of cracks and damage mechanisms in CFRP laminates.
Predicting the high strain rate behaviour of particulate composites using time-temperature superposition based modelling
Authors: Trivedi Akash R , Siviour Clive R
Published: September 2021

Polymeric particulate composites are widely used in engineering systems where they are subjected to impact loading – at a variety of temperatures – leading to high strain rate deformation. These materials are highly rate and temperature dependent, and this dependence must be well understood for effective design. It is not uncommon for many of these materials to display mechanical responses that range from glassy and brittle to rubbery and hyperelastic [1-3], due to their polymeric constituents. This makes accurate measurements and modelling not only necessary, but challenging. This is made more difficult by experimental artefacts present when traditional tools such as the split Hopkinson pressure (SHPB) or Kolsky bar are used to interrogate the high rate response of low-impedance materials. The transition from isothermal to adiabatic conditions as the rate of deformation increases also has an effect on the mechanical response, which cannot be neglected if the high rate behaviour is to be accurately predicted. In this paper, time-temperature superposition based frameworks that have enabled the high rate behaviour of neoprene rubber [4] and (plasticised) poly(vinyl chloride) [5] to be captured, will be extended to explore the high strain rate behaviour of unfilled natural rubber and several grades of glass microsphere filled natural rubber particulate composites.
Numerical modelling strategies using implicit and explicit methods to simulate quasi-static and dynamic three-points bend fracture tests of a ductile steel
Authors: Nozères Frédéric , Couque Hervé , Boulanger Rémi , Quirion Yann , Bailly Patrice , Limido Jérôme
Published: September 2021

Three-point bend fracture tests have been conducted at different loading rates with a quadratic martensitic steel. The failure energy has been found to increase with loading rate. To get insights in this increase a numerical investigation has been undertaken with different strategies using ABAQUS and IMPETUS softwares in order to address quasi-static and dynamic loading conditions.

Simulations were conducted with the ABAQUS software in order to carry out a comparative analysis of both implicit and explicit approaches. In addition to standard Finite Element Method (FEM) applied to quasi-static and dynamic conditions, the eXtended-Finite Element Method (X-FEM) was applied to quasistatic conditions. In both approaches, implicit and explicit, crack initiation and propagation were governed by a critical plastic strain threshold combined with a displacement-based damage evolution criterion.

Simulations conducted with the IMPETUS software use an explicit approach and second order elements for both quasi-static and dynamic loading conditions. A node-splitting method using an energy-based damage criterion was employed to simulate the crack initiation and propagation.

Experimental data and numerical results have been compared, allowing to determine the ability of these two softwares to simulate accurately three-point bend fracture tests.
Diffraction Peak Broadening Anisotropy of Shock Loaded Uranium
Authors: Shestakov Alexander , Belyaev Dmitry
Published: September 2021

Analysis of angular dependences of the diffraction peak broadening observed in α-uranium in as-received state, after loading by converging spherical shock wave, low-speed uniaxial deformation, and annealing at 850°С has been presented in this work. Broadening anisotropy identical for all the states investigated has been demonstrated. The authors have attempted to explain the phenomena by Young’s modulus anisotropy of uranium or the crystallite orientation relative to the load applied under plastic deformation.
Evaluation of Compressive and Energy Absorption Characteristic of a Closed-cell Polymeric Foam subject to Dynamic Loading
Authors: Kawano Takahiro , Takase Yuta , Kojima Tomohisa , Yamada Hiroyuki , Tateyama Kohei , Tsuji Tomoaki
Published: September 2021

Foamed plastics have been used in many engineering fields because of their superiority in low density, energy absorption, thermal insulation, and acoustic damping capacities. With foams, it is known that the microstructure of cells directly relates to macroscopic deformation behaviour. However, mechanical properties based on microstructures composed of non-uniform cells have not been fully understood. This study aims to clarify the mechanical properties grounded on microstructures of foamed plastics subjected to dynamic loading. The quasi-static and dynamic compression test was carried out using foamed plastic with anisotropy in the cell structure, then the strain rate dependence of deformation and energy absorption characteristics was investigated. It was confirmed that the local buckling of the cells was the dominant deformation mode in the plastic collapse of the test piece. It was also confirmed that cell buckling was initiated around the middle in the height after the plastic collapse, then propagated to the whole specimen in both the quasi-static and dynamic tests by using digital image correlation. The stress-strain relationships and the amount of absorbed energy showed strain rate dependence owing to the deformation mode in which the local buckling of the cells is dominant.
The Phenomenon of the “First Stress Peak” at the Yielding in the Dynamic Compression Tests of FCC and BCC Microalloyed Structures
Authors: Błoniarz Remigiusz , Majta Janusz , Trujillo Carl P. , Cerreta Ellen K. , Muszka Krzysztof
Published: September 2021

In the presented work two grades of steel i.e. microalloyed ferrite (M_F) and microalloyed austenite (M_A) where subjected to the grain refinement processes using MaxStrain system and thermomechanical rolling. The wide range of grain size, starting from 200 µm down to submicrometer level was produced in this way. The specimens of both steels were subjected to the dynamic compression tests using the Split Hopkinson Pressure Bar (SHPB) apparatus and applying the strain rates in the range between ε˙ = 3750s-1 and ε˙ = 6000s-1. In addition, different temperatures were used in the tests, i.e.200 °C and 400 °C. The first peak of stress which is observed during elastic-plastic transition during the dynamic compression tests can be treated as a characteristic feature of the tested material. The results obtained in the present investigations showed a significant dependence of the “first stress peak” in the dynamic compression curve on the degree of the microstructure refinement for the samples of M_F and almost complete absence of this dependence for M_A.
Comparative analysis of dynamic strength and impact toughness of pipe steels
Authors: Bragov Anatoly , Konstantinov Alexander , Lomunov Andrey , Kruszka Leopold
Published: September 2021

To study the dynamic strength of pipe steels, a cycle of dynamic tests of three grades of pipeline steels (X80, X90, and X100) was performed, which included three types of experiments based on the Kolsky method: uniaxial tension of smooth specimens, as well as tension of specimens with a V-shaped annular notch and Charpy impact test according to the three-point bending pattern of beam-type specimens with a V-notch. In the last two cases, the fracture force and impact toughness, as well as the nominal fracture stress in the specimen, were determined. To assess the effect of “cold brittleness” and determine the temperature of the ductile-brittle transition, the specified test cycle was carried out in the temperature range from +20°C to –100°C. As shown by the test results, the studied steels have a fairly high ductility: the elongation at break is 25-30%. Therefore, the destruction of specimens directly in the first load cycle is not always possible. The use of an original system for registering additional loading cycles makes it possible to determine in which loading cycle the specimen ruptured. The limiting characteristics of plasticity (ψ and δ) of all tested steel grades are weakly dependent on both the strain rate and temperature (within the range of their variation). Whereas the impact toughness of steels significantly (2-3 times) decreases with a decrease in temperatures from room temperature to –100°C.
High Strength Steel (HSS) characterization for numerical simulation of defence applications: from data collection to triaxiality model validation
Authors: Mespoulet Jerome , Habdulhamid Hakim , Deconinck Paul
Published: September 2021

This paper details the methodology developed to fit a material strength/failure model with mesh sensitivity, strain rate influence and triaxiality effect on plastic failure for a blast/ballistic configuration for a HSS plate. Data collection in different loading conditions in quasi-static and dynamic regimes has been done, following a given tests matrix based on the customer phenomenological analysis. A complete set of parameters has been find by numerically reproduce the tests and find the best compromise to fit all the tests performed with a unique set. Tests on large square clamped plates have been performed with three nose shapes (flat, hemispheric and conical) to validate the set of parameters. One case with perforation and another at failure initiation have been done for each geometry. Numerical works using the final set of parameters have shown very good agreement in the various impact conditions.
Effects of elevated temperature on a tungsten alloy at high strain-rate
Authors: Cadoni Ezio , Dotta Matteo , Forni Daniele
Published: September 2021

The effects of elevated temperature at high strain rate of a commercial tungsten alloy were investigated. The tests were carried-out at high strainrate (from 850 to 2200 1/s) by means of a Split Hopkinson Tension Bar device on round specimens having diameter and gauge length of 2mm and 5 mm, respectively. The thermal conditions were obtained by means of a water-cooled induction heating system on the specimen mounted on the SHTB. The dependence of ultimate tensile strength on temperature was found to decrease, while the failure strain increased with temperature. The strain rate linearly growths with the temperature.
Tensile behaviour of Inconel 718 alloys under extreme conditions of temperature and strain-rate
Authors: Cadoni Ezio , Forni Daniele , Mazzucato Federico , Valente Anna
Published: September 2021

Nickel-based superalloys are widely used in critical applications where structural components are subjected to harsh operating conditions such as elevated temperatures and high strain-rate. These alloys are also among the most hard-to-cut materials. For this reason, some critical components with complex geometrical features along with critical dimensions cannot easily manufactured by conventional technologies. A rising disruptive Additive Manufacturing (AM) technique, namely powder-based Laser Metal Deposition (LMD), is able to overcome these limitations in terms of manufacturing costs, tool wear, as well as lead time. As a consequence, the mechanical response under harsh condition of additively manufactured Nickel-based superalloys has to be accurately understood in order to guarantee the reliability of the structural parts made with them. Presently very few researches were addressed to study the dynamic tensile behaviour of Inconel 718 produced by additive manufacturing under high strain-rate combined with elevated temperature. To overcome this lack, the coupled effect of strain rate (0.001 s−1, 250 s−1 and 800 s−1) and temperature (20°C, 350°C and 550°C) on the tensile properties of Inconel 718 alloys produced through cast and additive manufacturing technologies has been experimentally studied. The experiments were also addressed to investigate and compare the flow stress behaviour in function of strain rate and temperature considering the differences in terms of microstructure. A modest strain-rate sensitivity has been observed for both as-cast and as-built material, as well as a moderate decrease of the mechanical strengths has been highlighted for increasing temperatures. Finally, comparable mechanical behaviour has been observed between additively manufactured samples produced with a power laser of 400W and as-cast samples.
Dynamic properties of additively manufactured tantalum
Authors: Cotton Matthew , Girling Beth
Published: September 2021

In this study a series of gas gun plate impact experiments have been conducted on samples of wire arc AM tantalum to investigate the high strain rate behaviour of the material, including tensile failure (spall) mechanisms. Conventionally processed tantalum was fielded alongside the AM material to provide a direct comparison under identical loading conditions. In-situ velocimetry data was supported by pre-shock characterisation of the samples to supply information on the initial material microstructure, and to link these features to the observed differences in dynamic behaviour. Additional post-shock analysis of the damaged region in the samples provided further insight into the failure process.