Prototype experiments were carried out on the explosion-proof performance of the RC blast wall.The mass of TNT detonated in the experiments is 5 kg and 20 kg respectively.The shock wave overpressure was tested in diff...Prototype experiments were carried out on the explosion-proof performance of the RC blast wall.The mass of TNT detonated in the experiments is 5 kg and 20 kg respectively.The shock wave overpressure was tested in different regions.The above experiments were numerically simulated,and the simulated shock wave overpressure waveforms were compared with that tested and given by CONWEP program.The results show that the numerically simulated waveform is slightly different from the test waveform,but similar to CONWEP waveform.Through dimensional analysis and numerical simulation under different working conditions,the equation for the attenuation rate of the diffraction overpressure behind the blast wall was obtained.According to the corresponding standards,the degree of casualties and the damage degree of the brick concrete building at a certain distance behind the wall can be determined when parameters are set.The above results can provide a reference for the design and construction of the reinforced concrete blast wall.展开更多
Blast wall can prevent vehicles from approaching the protective building and can reduce the destructive power of shock wave to a certain extent.However,majority of studies on blast walls have some shortcomings.The exp...Blast wall can prevent vehicles from approaching the protective building and can reduce the destructive power of shock wave to a certain extent.However,majority of studies on blast walls have some shortcomings.The explosion test data are few.Most exsiting studies focus on the propagation of shock wave and the influence of blast wall on the propagation of shock wave.Discussion on the main parameters of blast wall design is meagre,such as the design of safety distance,the distance from the blast wall to the protective building,height and width of the blast wall.This paper uses the finite element programme LS-DYNA to design the blast wall.To analyze the convergence of the finite element model and to determine the mesh size of the model,this paper establishes several finite element models with different sizes of meshes to verify the model.Then,the overpressure distribution of the shock wave on the protective building is simulated to implement the blast wall design.The geometric parameters of the blast wall are preliminarily determined.And the influence of the safety distance on the overpressure of the building surface is mainly discussed,so as to determine the final design parameters.When the overpressure is less than 2 kPa,it is considered that there will be no damage to people caused by flying fragments.Eventually,the blast wall height is 3 m,the thickness is 1 m,and the safety distance is 35 m.The proposed method is used to demonstrate the design method,and the final design parameters of the blast wall can thus be used for reference.展开更多
A monitoring method that has been designed for the first time for blast furnace wall with copper staves manufactured in China was introduced. Combining the method of ＂inverse problem＂ and the concept ＂non-inverse p...A monitoring method that has been designed for the first time for blast furnace wall with copper staves manufactured in China was introduced. Combining the method of ＂inverse problem＂ and the concept ＂non-inverse problem＂, the monitoring program for blast furnace wall with copper staves has been realized, which can be used to calculate online the accretion thickness and temperature of hot surface of copper staves after obtaining the values of thermocouples of copper staves. The accretion state obtained in the actual investigation has proved that the result of the program is correct. The monitoring program shows that the accretion would easily fluctuate when the accretion layer is extremely thick or thin, thereby the stable and smooth operation of the blast furnace is hindered. By maintaining appropriate accretion thickness, both long campaigns and high productivity of the blast furnace can be achieved; furthermore, it can also optimize the operation of blast furnace and maximize its production. Approximately 30--50 mm in thickness of accretion layer is maintained on the wall of Shougang blast furnace 2, which can meet the requirement for obtaining both long campaign and high productivity.展开更多
In this study, the relationship between hearth wall erosion and deadman permeability was investigated based on the change in the hearth bottom and hearth sidewall temperatures. Additionally, the operation practice for...In this study, the relationship between hearth wall erosion and deadman permeability was investigated based on the change in the hearth bottom and hearth sidewall temperatures. Additionally, the operation practice for controlling hearth wall erosion in the large No. 1 blast furnace at Baosteel was also investigated. The reasons for the decrease in the permeability of deadman coke were analyzed, and measures for improving the permeability of deadman coke and controlling hearth wall temperature rising were described. The results show that a decrease in deadman coke permeability is the main reason for refractory temperature increase and hearth wall erosion. This indicates the importance of monitoring changes in hearth working conditions and taking appropriate measures to maintain sufficient permeability of the deadman and balance the hot metal flow and drainage of slag. At this rate, the decline in the hearth bottom temperature and fast rising of the hearth wall temperature can be restrained.展开更多
为研究真实工况下人员在爆炸冲击波作用下的动态响应特性,开展某型云爆弹静爆作用下工事内仿人形装置(Anthropomorphic Test Device,ATD)和绵羊的毁伤试验研究。采用爆炸测试装置和简易假人作为研究对象,通过6发爆炸试验分析爆炸冲击波...为研究真实工况下人员在爆炸冲击波作用下的动态响应特性,开展某型云爆弹静爆作用下工事内仿人形装置(Anthropomorphic Test Device,ATD)和绵羊的毁伤试验研究。采用爆炸测试装置和简易假人作为研究对象,通过6发爆炸试验分析爆炸冲击波在ATD表面传播规律,开展2种人员损伤预测模型的对比分析。研究结果表明:在本试验工况下,冲击波和崩落的混凝土碎块是主要的毁伤元;爆炸冲击波在ATD表面首先发生反射,随后绕射至其他部位,压力曲线表现出非典型冲击波特征,反射叠加效应明显;在典型冲击波特征正压作用时间区间内,由于Axelsson损伤模型线性阻尼项的影响,求解的胸壁运动速度呈现出先增大至峰值后降低的现象;Axelsson损伤模型与UFC 3-340-02规范相比,在人员损伤预测方面相对保守。所得研究结果可为工程应用及毁伤评估提供参考。展开更多
基金funded by Key R&D Projects in Hubei Province (Grant No.2020BCA084)Innovative Group Project of Hubei Natural Science Foundation (Grant No.2020CFA043)。
文摘Prototype experiments were carried out on the explosion-proof performance of the RC blast wall.The mass of TNT detonated in the experiments is 5 kg and 20 kg respectively.The shock wave overpressure was tested in different regions.The above experiments were numerically simulated,and the simulated shock wave overpressure waveforms were compared with that tested and given by CONWEP program.The results show that the numerically simulated waveform is slightly different from the test waveform,but similar to CONWEP waveform.Through dimensional analysis and numerical simulation under different working conditions,the equation for the attenuation rate of the diffraction overpressure behind the blast wall was obtained.According to the corresponding standards,the degree of casualties and the damage degree of the brick concrete building at a certain distance behind the wall can be determined when parameters are set.The above results can provide a reference for the design and construction of the reinforced concrete blast wall.
基金This work was supported by the National Natural Science Foundation of China(No.51878507).
文摘Blast wall can prevent vehicles from approaching the protective building and can reduce the destructive power of shock wave to a certain extent.However,majority of studies on blast walls have some shortcomings.The explosion test data are few.Most exsiting studies focus on the propagation of shock wave and the influence of blast wall on the propagation of shock wave.Discussion on the main parameters of blast wall design is meagre,such as the design of safety distance,the distance from the blast wall to the protective building,height and width of the blast wall.This paper uses the finite element programme LS-DYNA to design the blast wall.To analyze the convergence of the finite element model and to determine the mesh size of the model,this paper establishes several finite element models with different sizes of meshes to verify the model.Then,the overpressure distribution of the shock wave on the protective building is simulated to implement the blast wall design.The geometric parameters of the blast wall are preliminarily determined.And the influence of the safety distance on the overpressure of the building surface is mainly discussed,so as to determine the final design parameters.When the overpressure is less than 2 kPa,it is considered that there will be no damage to people caused by flying fragments.Eventually,the blast wall height is 3 m,the thickness is 1 m,and the safety distance is 35 m.The proposed method is used to demonstrate the design method,and the final design parameters of the blast wall can thus be used for reference.
基金Item Sponsored by National Natural Science Foundation of China(60472095)
文摘A monitoring method that has been designed for the first time for blast furnace wall with copper staves manufactured in China was introduced. Combining the method of ＂inverse problem＂ and the concept ＂non-inverse problem＂, the monitoring program for blast furnace wall with copper staves has been realized, which can be used to calculate online the accretion thickness and temperature of hot surface of copper staves after obtaining the values of thermocouples of copper staves. The accretion state obtained in the actual investigation has proved that the result of the program is correct. The monitoring program shows that the accretion would easily fluctuate when the accretion layer is extremely thick or thin, thereby the stable and smooth operation of the blast furnace is hindered. By maintaining appropriate accretion thickness, both long campaigns and high productivity of the blast furnace can be achieved; furthermore, it can also optimize the operation of blast furnace and maximize its production. Approximately 30--50 mm in thickness of accretion layer is maintained on the wall of Shougang blast furnace 2, which can meet the requirement for obtaining both long campaign and high productivity.
文摘In this study, the relationship between hearth wall erosion and deadman permeability was investigated based on the change in the hearth bottom and hearth sidewall temperatures. Additionally, the operation practice for controlling hearth wall erosion in the large No. 1 blast furnace at Baosteel was also investigated. The reasons for the decrease in the permeability of deadman coke were analyzed, and measures for improving the permeability of deadman coke and controlling hearth wall temperature rising were described. The results show that a decrease in deadman coke permeability is the main reason for refractory temperature increase and hearth wall erosion. This indicates the importance of monitoring changes in hearth working conditions and taking appropriate measures to maintain sufficient permeability of the deadman and balance the hot metal flow and drainage of slag. At this rate, the decline in the hearth bottom temperature and fast rising of the hearth wall temperature can be restrained.
文摘为研究真实工况下人员在爆炸冲击波作用下的动态响应特性,开展某型云爆弹静爆作用下工事内仿人形装置(Anthropomorphic Test Device,ATD)和绵羊的毁伤试验研究。采用爆炸测试装置和简易假人作为研究对象,通过6发爆炸试验分析爆炸冲击波在ATD表面传播规律,开展2种人员损伤预测模型的对比分析。研究结果表明:在本试验工况下,冲击波和崩落的混凝土碎块是主要的毁伤元;爆炸冲击波在ATD表面首先发生反射,随后绕射至其他部位,压力曲线表现出非典型冲击波特征,反射叠加效应明显;在典型冲击波特征正压作用时间区间内,由于Axelsson损伤模型线性阻尼项的影响,求解的胸壁运动速度呈现出先增大至峰值后降低的现象;Axelsson损伤模型与UFC 3-340-02规范相比,在人员损伤预测方面相对保守。所得研究结果可为工程应用及毁伤评估提供参考。
