Yao Xu, Siyue Gao, Jianzhong Zhang, Yanlei Liu, Weibin Zhang, Jun Wang, Hui Wang, Shujing Wang, Zhiqiang Ma, Pengwan Chen, Rui Liu
{"title":"Using a fiber Bragg grating technique to investigate temperature cycling strain of pressed TATB‐based polymer‐bonded explosives","authors":"Yao Xu, Siyue Gao, Jianzhong Zhang, Yanlei Liu, Weibin Zhang, Jun Wang, Hui Wang, Shujing Wang, Zhiqiang Ma, Pengwan Chen, Rui Liu","doi":"10.1002/prep.202400032","DOIUrl":"https://doi.org/10.1002/prep.202400032","url":null,"abstract":"Pressed 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB)‐based polymer‐bonded explosive (PBX) exhibits significant anisotropic and irreversible expansion characteristics during temperature cycling, resulting in both safety and service issues. The anisotropic and irreversible expansion properties of PBX have shown to be closely related to the microstructures, including explosive crystals, binders, micro voids, el. Fiber Bragg grating (FBG) technology has advantages of high reliability, accuracy, and sensitivity, which is more conducive to real‐time capture of the changes in strain throughout the temperature cycling. In this study, temperature cycling strain monitoring experiments of PBX pressed under different thermal–mechanical coupling loading conditions were studied using FBG technology. The effect of the pressing parameters on the anisotropic and irreversible expansion characteristics of the PBX's during temperature cycling was measured and analyzed, taking into account potential microstructural factors such as crystal orientation, binders, and porosity. The results indicated that the strain on the side and top of PBX cylinders were distributed with increasing strain in the direction of higher density. The strain stratification was significant during the high‐temperature stage of temperature cycling and was not obvious during the low‐temperature stage. The degree of strain stratification decreased with an increase in temperature cycling cycles and increased with higher pressing temperatures. The anisotropic expansion of PBX cylinders increased with an increase in temperature during cycling and decreased with a reduction in temperature. The axial expansion degree of PBX cylinders pressed under different compression conditions in the later cycles of temperature cycling is consistent with the different crystal orientations intensity inside them.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141507181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Youcai Xiao, Kelei Pei, Yu Zou, Yong Han, Tianyuan Gong, Xiangdong Xiao, Yi Sun
{"title":"Dynamic damage and non‐shock ignition behavior of polymer bonded explosive under lower velocity impact","authors":"Youcai Xiao, Kelei Pei, Yu Zou, Yong Han, Tianyuan Gong, Xiangdong Xiao, Yi Sun","doi":"10.1002/prep.202300016","DOIUrl":"https://doi.org/10.1002/prep.202300016","url":null,"abstract":"The accidental ignition of polymer‐bonded explosives (PBXs) caused by hot spots has been the focus of domestic and international research. Micro‐crack friction plays a crucial role in the formation these hot spots. In this study, confined tests were conducted to investigate the ignition response of PBX under impact loading. The experimental results revealed that the PBX underwent ignition under the given conditions of a pressure load with a pulse width of 50 μs and an amplitude of 638 MPa. The viscoelastic statistical cracking model (Visco‐SCRAM) and hot‐spot ignition model were used to describe the damage behaviors and ignition responses of the PBX. The simulation results revealed that more severe damage occurs at the center of the impact face and its vicinity under confined impact conditions, which is consistent with the observed post‐test samples. Additionally, simulation results also predict a trapezoidal shape for the severely damaged region within the PBX. The findings of this study provide insights for understanding the damage behavior and the critical ignition of PBX under impact loading.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141516873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ch Devi Vara Prasad, P. Kanakaraju, R. Vinu, Abhijit P. Deshpande
{"title":"Synthesis of HHTPB by partial hydrogenation of HTPB using copper chromite as a catalyst","authors":"Ch Devi Vara Prasad, P. Kanakaraju, R. Vinu, Abhijit P. Deshpande","doi":"10.1002/prep.202300339","DOIUrl":"https://doi.org/10.1002/prep.202300339","url":null,"abstract":"HTPB (hydroxyl‐terminated polybutadiene) is a well‐established binder in the composite solid propellant owing to its excellent compatibility with ammonium perchlorate (AP) and aluminium (Al) particles in giving rise to optimal ballistic and mechanical properties. Efforts are being made to improve the ballistic properties further, such as specific impulse. One way of increasing the specific impulse is to hydrogenate HTPB, which decreases the molecular mass of the combustion product gases. This paper is a summary of efforts in synthesizing hydrogenated HTPB (HHTPB) using copper chromite (CC) as a catalyst. A novel synthesis methodology is developed for HHTPB using a temperature‐programmed batch reactor with a variable speed stirrer and an instrumentation system to maintain the desired liquid reactant temperature. A process cycle is developed that includes addition sequence and reaction time. The product is analyzed using <jats:sup>1</jats:sup>H‐NMR and FTIR to estimate the degree of hydrogenation and the geometrical isomers respectively. The estimated apparent equilibrium rate constants from the degree of hydrogenation values are respectively 74 and 2034 L/(mol MPa) for non‐catalyzed and catalyzed systems, indicating the effectiveness of the catalyst. This is also substantiated by the reduction in Gibbs free energy (ΔG), to an extent of 4.48 kJ/mol. Thermogravimetry examination indicates that the decomposition temperature of HHTPB produced by the catalytic method is marginally higher compared to HTPB. DSC curves indicate that the decomposition enthalpy of HHTPB is higher than that of HTPB. In summary, this paper proposed and validated a novel method in the preparation of HHTPB using copper chromite.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141516874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ki T. Wolf, Joel T. Clemmer, Michael L. Hobbs, Michael Kaneshige, Dan S. Bolintineanu, Judith A. Brown
{"title":"Investigation of thermal damage in explosive bridgewire detonators via discrete element method simulations","authors":"Ki T. Wolf, Joel T. Clemmer, Michael L. Hobbs, Michael Kaneshige, Dan S. Bolintineanu, Judith A. Brown","doi":"10.1002/prep.202300305","DOIUrl":"https://doi.org/10.1002/prep.202300305","url":null,"abstract":"Exploding bridgewire (EBW) detonators are used to rapidly and reliably initiate energetic reactions by exploding a bridgewire via Joule heating. While the mechanisms of EBW detonators have been studied extensively in nominal conditions, comparatively few studies have addressed thermally damaged detonator operability. We present a mesoscale simulation study of thermal damage in a representative EBW detonator, using discrete element method (DEM) simulations that explicitly account for individual particles in the pressed explosive powder. We use a simplified model of melting, where solid spherical particles undergo uniform shrinking, and fluid dynamics are ignored. The subsequent settling of particles results in the formation of a gap between the solid powder and the bridgewire, which we study under different conditions. In particular, particle cohesion has a significant effect on gap formation and settling behavior, where sufficiently high cohesion leads to coalescence of particles into a free‐standing pellet. This behavior is qualitatively compared to experimental visualization data, and simulations are shown to capture several key changes in pellet shape. We derive a minimum and maximum limit on gap formation during melting using simple geometric arguments. In the absence of cohesion, results agree with the maximum gap size. With increasing cohesion, the gap size decreases, eventually saturating at the minimum limit. We present results for different combinations of interparticle cohesion and detonator orientations with respect to gravity, demonstrating the complex behavior of these systems and the potential for DEM simulations to capture a range of scenarios.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141516872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Huanhuan Gao, Fang Wang, Hui Liu, Yukun Chen, Jianzhong Liu
{"title":"Research progress and prospects on agglomeration models and simulation methods of aluminum particles in aluminum‐based composite propellants","authors":"Huanhuan Gao, Fang Wang, Hui Liu, Yukun Chen, Jianzhong Liu","doi":"10.1002/prep.202400056","DOIUrl":"https://doi.org/10.1002/prep.202400056","url":null,"abstract":"The agglomeration of aluminum during the combustion of solid propellants considerably impacts engine operation and has been widely studied in recent years. The characteristics of aluminum agglomeration in aluminum‐based composite propellants have been studied via experiments and simulations. In this study, the agglomeration process and the characteristics of agglomerated particles are summarized. Agglomeration models and simulation methods have garnered considerable attention because they are not influenced by experimental conditions, are economical, and have minimal restrictions. Therefore, five agglomeration models and four simulation methods are introduced herein to investigate agglom eration in aluminum‐based composite propellants. By analyzing the advantages and disadvantages of these models and methods, deeper agglomeration mechanisms can be explored and new directions for suppressing agglomeration can be identified to mitigate agglomeration issues. These efforts can support and guide the design of solid rocket propellants and the safe operation of rocket engines.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141516879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuhong Yuan, Yinsheng Huang, Mingcheng Ge, Ye Zhong, Zhimin Li
{"title":"Energetic transition metal complexes based on 1‐allylimidazole and nitrocyanamide: Syntheses, characterizations and catalytic performances on the thermal decomposition of ammonium perchlorate","authors":"Yuhong Yuan, Yinsheng Huang, Mingcheng Ge, Ye Zhong, Zhimin Li","doi":"10.1002/prep.202300342","DOIUrl":"https://doi.org/10.1002/prep.202300342","url":null,"abstract":"To explore combustion catalysts for solid propellants, four novel energetic coordination compounds were prepared with the anion of nitrocyanamide (NCA) as the ligand and 1‐allyl‐imidazole (AIM) as the ligand, and transition metals Mn, Co, Ni, and Cu as the central ions. The structures of these compounds were [Mn(AIM)<jats:sub>4</jats:sub>] (NCA)<jats:sub>2</jats:sub> (1), [Co(AIM)<jats:sub>4</jats:sub>](NCA)<jats:sub>2</jats:sub> (2), [Ni(AIM)<jats:sub>4</jats:sub>](NCA)<jats:sub>2</jats:sub> (3), [Cu(AIM)<jats:sub>4</jats:sub>](NCA)<jats:sub>2</jats:sub> (4). The results showed that all of the compounds possessed high energy density, and compound 2 had a mass energy density (<jats:italic>E<jats:sub>g</jats:sub></jats:italic>) of 17.9 kJ g<jats:sup>−1</jats:sup> and a volume energy density (<jats:italic>E<jats:sub>v</jats:sub></jats:italic>) of 25.59 kJ cm<jats:sup>−3</jats:sup>. The catalytic effect of these compounds on the thermal decomposition of ammonium perchlorate (AP) was studied using DSC. The addition of 5 % catalyst to AP samples advanced the high‐temperature decomposition temperature and significantly increased the heat release. Compound 4 exhibited the best catalytic performance, with an increased heat release of 1739 J g<jats:sup>−1</jats:sup>, decomposition temperature advanced by 88.2 °C, and activation energy reduced to 74.74 kJ mol<jats:sup>−1</jats:sup>. These results demonstrate the potential of these compounds as combustion catalysts for solid propellants.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141516789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}