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Lead styphnate is a primary explosive with low brisance, and is extensively applied into civil and military devices. Whereas the electrostatic sensitivity of LTNR is extremely high, it is disadvantageous for the safety of ignition system. In this paper, a novel initiator was integrated with Al/MoO3 multilayer film and bridge wire by magnetron sputtering. The thickness of Al/MoO3 multilayer was 3um with period of 20nm/30nm. The heat release of Al/MoO3 multilayer film was and 1164J/g, which was characterized by differential scanning calorimetry (DSC). And the combustion speed of film was about 5.3 m/s, it was characterized by high speed cameral and laser ignition system. The firing sensitivities was measured by Langly method, the 50% and 99.9% firing-current sensitivity of initiator was 0.08A and 0.11A, respectively, and the 50% and 99.9% firing-voltage sensitivity of initiator was 2.30V and 2.56V, respectively. The firing sensitivities of Al/MoO3 multilayer film was almost equal to the LTNR. The insensitive ignition composition of B-KNO3 tablet was easily fired with in the gap of 2.12 mm. And the initiator can easily fire the lead azide in detonator. All of these, it is suggested that Al/MoO3 multilayer film will expect to be a substitute for LTNR and improve the ignition ability and safety of ignition system and has a significant influence on the design of explosive devices.

The article describes the results of laboratory tests of the algorithm of control of programmable detonators designed for tandem systems. Control elements were made on the basis of microcontrollers using RISC architecture. The detonator has a system to quickly excite the precursor charge and can be programmed at any time to delay the detonation of the main charge. The lack of delay in excitation of the precursor charge was realized using a comparator. The article presents the results of preliminary laboratory tests of the control algorithm of the executed system. The flexibility of the solution to program any delay time for the excitation of the main load provides a wide range of practical applications.

Blasting is an effective methods of tunnel excavation, but blasting vibration damage will occur in the construction process. In order to study the blasting vibration of the downlink tunnel, the blasting vibration of the upper part of a tunnel in yunnan was monitored The results show that the vertical vibration velocity is higher than the other two axial vibration velocity, and there is obvious elevation amplification effect in the blasting vibration propagation process. In this test condition, the impact range of blasting vibration is 22m, which will not affect the village. According to HHT analysis, the blasting vibration energy is mainly concentrated in the low-frequency interval, while the high frequency interval vibration energy is small; The instantaneous response spectrum of blasting vibration energy can reflect the number of detonators used for the maximum single-end charge, and there is a surge of energy in the process of blasting vibration energy transmission. At the same time, the expansion of the air face can effectively reduce the transfer of blasting vibration energy. The results show that the propagation of blasting vibration energy can be effectively controlled by controlling the maximum charge of explosive and increasing the blank surface.

In the process of initiating detonation of explosive materials, the environmental parameters have serious nonlinear effects. Aiming at the problem of the variation, uncertainty and nonlinearity of component parameters which can not be solved by linear function, The Volterra series model is combined with the gene expression programming, The algorithm uses the Volterra series to accurately reflect the characteristics of the nonlinear system to describe the initiation process of the detonator, so that no matter how the environmental parameters change, The intrinsic characteristics of initiating explosive are not changed, and the GEP algorithm overcomes the shortcomings of traditional identification methods and identifies the correct model. The simulation results show that this method can accurately and quickly identify the initiation process.

Green primary explosives have gained wide attention for environmental protection. A potential novel lead-free primary explosive, Al/Fe2O3/RDX hybrid nanocomposite was prepared by ultrasonic mixing, and its safety properties are discussed in detail. Results showed that their sensitivity and safety properties were a function of the specific surface area and proportions of their ingredients. Their impact sensitivity fell and their static discharge, flame, and hot bridge wire sensitivities rose as the specific surface area of nano-Fe2O3 increased. As the amount of Al/Fe2O3 nanothermite was increased, its impact sensitivity fell and its flame sensitivity rose, their static discharge and hot bridge wire sensitivities, however, followed an inverted &ldquo, U&rdquo, type change trend and were determined by both the particle size of the ingredients and the resistance of the nanocomposite. Their firing properties in an electric detonator depended on the proportion of the constituents. Thus, green nanoscale primary explosives are appropriate for a range of initiatory applications and can be created by adjusting their specific surface area and the amount of their constituents.

In this paper we analyze the universal mathematical model of the electric firing circuit representing its constituent parts in the form of quadrupoles connected to each other. By means of this model we analyze the state of the electric firing circuit effected by the four most frequently encountered factors: direct current, alternating current, exponential effect, generalized effect. We have calculated the transmission coefficients for current and voltage for this circuit based on which we have determined the dependence for current distribution between the electric detonators in the circuit and the probabilities of their activation. The maximum possible number of simultaneously initiated electric detonators is determined. A numerical example of calculation is given. Practical recommendations on the design of blasting devices, on the optimal electromagnetic compatibility of the electric firing circuit, as well as on increasing the safety and reliability of blasting operations are given.

It is generally believed that stress wave superposition does occur and plays an important role in cutting blasting with a single free surface, in which explosive columns of several blast holes with short spacing are simultaneously initiated. However, considering the large scatter of pyrotechnic delay detonators that are used in most underground metal mines in China, the existence of stress wave superposition and the influence of this effect on rock fragmentation are questionable. In the present study, the stress wave interaction in short-delay blasting with a single free surface was studied through the use of the LS-DYNA code. Stress waves induced by two blast holes blasting with different delays were compared with the single blast hole case, and the effects of delay time, detonating location and spacing on stress wave superposition were investigated. The numerical results showed that for blast holes with a 1 m spacing, stress wave interaction only occurs when the delay time is 0 ms and does not occur for blasting with delays of more than 1 ms. An increase in the duration of a stress wave via optimizing the detonation location does not improve the stress wave interaction. For a 1 ms delay, stress wave superposition only occurs when the spacing is more than 4 m, which is a rare case in practice. The results indicated that the occurrence of stress wave superposition for blasting with a single free surface is strictly limited to conditions that would be difficult to achieve under the existing delay accuracy of detonators. Therefore, it is unrealistic to improve fragmentation via the stress wave interaction in field blasting. Furthermore, the numerical results of the stress wave interaction also show that there would be a great potential to reduce the hazardous vibrations induced by short-delay blasting by using electronic detonators with better control of delays in an order of several milliseconds.

To solve the problem of detecting for Missile Initiating Devices (MID) before launching, an intelligent equivalent equipment based on Field Programmable Gate Array (FPGA) is designed and realized. The system adopts microchip EP3C16F256C8 and its peripheral circuit to equal to the electric detonator resistor while passage-testing. It also can be used to detect the sequence of electric information while signal testing. Through passage-testing, experiment of current timing and voltage timing shows that the electric detonator resistor value and the sequence width can meet the design requirement. The testing is investigated on the experimental platform. Also, the system has the advantages of high reliability, good maintenance and strong practicality. It can be widely promoted and applied.

This paper analyzes the design principle of integrated laser detonator, introduces the design method of integrated laser Detonators. Based on the integrated laser detonator, structure, laser energy -exchange device, circuit design and the energetic material properties and the charge parameters, developed a high level of integration Antistatic ability Small size of the integrated laser prototype Detonator. The laser detonator prototype antistatic ability of 25 kV. The research of this paper can solve the key design of laser detonator miniaturization and integration of weapons and equipment, satisfy the electromagnetic safety and micro weapons development of explosive demand.

Nowadays, explosion phenomena are one of the exciting research especially in military field. In this paper, the study focus on investigation of the detonator triggering effect when subjected to radio frequency energy exposure from wireless local area network (WLAN). Electric detonator characteristics was used to design the test configuration to check the existence of current fluctuation in the wires during Wi-Fi exposure. The main interest is to observe for such cases, any premature fluctuation in the current flow connected to the detonator will be instigated prematurely upon setting up any wireless transmission during blast testing. Therefore, parameters such as cable specification, distance and acceptable current fluctuation is being further analyses. Preliminary test has found that there is no prematurely effect and the testing can be further implemented using real life detonator without the influence of blast materials such as TNT or PETN.

A novel diagnostics method to measure the detonation electric effect was tested and verified against computerized models. Where standard diagnostics are used to measure currents, timings, and other particularly useful quantities, a novel copper antenna was created in order to detect and measure RF-signals (radio frequency) from high explosives (HE). With detonation velocities, pressures, and arrival times resolved from multiple diagnostics, including Rogowski coils5, Polyvinylidene Fluoride (PVDF) gauges, and Current Viewing Resistors (CVR), models created with ALE3D Hydro Codes then predict detonator performance and further qualify the copper antenna’s integrity as a capable diagnostic in quantifying RF emissions.

An empirical model equation for shock-pressure decay in PMMA was determined through a unique set of experiments employing detonator loading. Custom polymethyl methacrylate (PMMA) witness blocks were designed with monolithic architecture to house precise PMMA gaps with thicknesses ranging from 0-10 mm in nominal increments of 1 mm. The PMMA gaps separated detonator working surfaces from windowed photonic Doppler velocimetry (PDV) probes, and were designed to provide undistorted optical access for ultra-high-speed framing and digital-streak cameras. The shock wave image framing technique (SWIFT), and a new laser-backlit digital-streak diagnostic, simultaneously captured the temporal evolution of detonator-induced diverging shock waves within the PMMA gaps. The PDV diagnostic measured critical mass-velocity histories as the shocks exited the variable gap thicknesses. The multi-diagnostic data package was used to characterize the shock-pressure decay in PMMA as a function of shock-propagation time and PMMA thickness.

During the electrical explosion of bridge-wires and bridge-foils, the metal bridge undergoes rapid resistive-heating. The metal is rapidly expanded through solid, liquid, vapour and plasma phases. This study uses ALEGRA MHD, a Sandia National Laboratory magneto-hydrocode, to predict the formation of these metallic phases during the explosion process and determine the effects of surface heterogeneities on the spatial distribution of these phases. The simulations are compared against x-ray phase contrast radiographs of electrically exploded bridge-foils. From comparison of these data, it is evident that the meso-structure of the metallic foil dominates the explosion process and is something that should be controlled during the manufacturing processes for detonator designs.

Insensitive High Explosives (IHEs) increase safety in many types of uses. However, the safety comes at the cost of performance. Initiation of IHE requires large boosters and powerful detonators as well. Multipoint initiation is being utilized to exploit explosive wave interactions to create overdriven states, greatly facilitating the initiation of IHEs. This concept builds from recent explosive experiments where the minimum spot size for single-point initiation in PBX 9502 was determined. Below this threshold, PBX 9502 could not be initiated. This was then expanded to three initiation points, which were smaller than this threshold. Measurements of the velocity and pressure of the wave interactions were collected using Photon Doppler Velocimetry (PDV). Not only was initiation observed, but the resulting pressures at the double and triple points were found to be above the CJ state for PBX 9502. Based on these results, further tests were conducted to isolate and measure the longevity and pressure of this phenomenon using a series of cutback tests.

Photoactive explosives show promise to be relatively insensitive to impact and friction compared to pentaerythritol tetranitrate (PETN) and other detonator materials, but can be more easily initiated with laser light. Metal-ligand charge transfer (MLCT) complexes have been previously shown to have tunable explosive properties and absorption profiles, making them strong candidates for laser detonator materials. Here, we provide a summary of the synthesis and characterization of multiple iron-based MLCT complexes, as well as results from recent efforts to initiate detonation in a high-density PETN output pellet. Paths forward will be discussed.

Based on the smooth blasting method, the blasting parameters of the Beishan exploration tunnel have been designed. According to the principle of blasting parameters design, three kinds of cutting methods have been laid out, which are straight parallel hole cutting, single-wedge cutting, and double-wedge cutting. The other parameters such as the borehole number, the detonator segment, and the charge amount of each hole are also designed. Then, the blasting tests under different cutting methods were carried out in the field. The results show that all the three cutting methods can achieve good utilization ratio of blasting holes. The blasting effect of straight parallel hole cutting is good. The rock slag size of single-wedge and double-wedge cutting is uniform, which is beneficial to slag extraction. Moreover, the blasting vibration velocity and blasting energy have been analyzed. It is found that the energy distribution of single-wedge and double-wedge cutting is more uniform, mainly concentrated in the high-frequency part, while the energy of straight parallel hole cutting is more concentrated in the low-frequency part. Among many factors affecting blasting vibration velocity, besides the explosive quantity, it would also be easily influenced by the cutting way. It should be noticed that the blasting method includes numerous blasting parameters, which interact with each other. Those blasting parameters obtained were just limited to the cutting method, and the result and the theoretical knowledge could be applied to the blasting and excavation of the deep geoengineering and the HLW geo-disposal.

Although Bertram Hopkinson had a research interest in the dynamic strengths of materials, the bar technique he published in 1914 was developed to roughly determine the shapes of stress pulses produced by bullet impact and explosions. His pressure bar proved useful to the British explosives and armour industry during the Great War allowing them to improve their munitions. It also allowed the phenomenon of spall of metal plates produced by ballistic impact or by explosions to be understood. Another greater war had to occur before Hopkinson’s pressure bar was applied by Taylor, Davies and Volterra in the UK to the measurement of the dynamic compressive properties of explosives and polymers. Unlike after the First World War, why this research was thought important to the British armed forces during the Second World War was not explained in the declassified reports published once the war was over. Soon after the end of the Second World War, Kolsky made a number of improvements to the double Hopkinson bar system including using detonators to substantially increase the stresses that could be applied to specimens. This made possible for the first time the accurate determination of the dynamic compressive stress-strain curves of metals. Detonators are, however, impractical for all but defence labs to obtain and use. So an alternative method of loading was needed, and this was developed by Krafft and co-workers at the Naval Research Laboratory in Washington DC in the early 1950s. Their design used a gun to launch a projectile rod against one end of the double bar system and this American method eventually became standard in all laboratories that use the split Hopkinson pressure bar technique. However, it was not until the end of the 1970s that split Hopkinson bars began to be built in laboratories in an ever increasing number of countries around the world.

In detonators the “lost time” or “excess transit time” is the difference between the measured and calculated time for the reactive wave to transit the explosive charge in the detonator. The calcula...

The successful design of electro-explosive devices requires their safety characteristics as well as performance to be considered. In order to design components that pass the necessary safety tests an understanding is required of the way in which the various threats interact with the device and in particular the explosive fill(s). A prototype PETN chip slapper detonator has been subjected to a suite of electrical and mechanical threats. Insulted detonators have subsequently been examined using X-ray CT to assess the damage to the explosive fill. Using fundamental understanding of the initiation of PETN compacts, and chip design, an attempt has been made to understand the conditions at which reaction occurs, the parameters which may dictate the violence of such a reaction and the mechanism by which reaction occurs in order to design detonators which contain the necessary mitigating features.

The off-normal detonation behavior of two plastic-bonded explosive (PBX) formulations was studied using explosively-driven aluminum fragments created by two types of detonators. A generic aluminum-cupped detonator contained 100 mg of PETN which was sufficient to fragment the aluminum into hundreds of sub-mm particles moving at hypersonic velocity; for comparison, a Teledyne RISI® RP-80 was also tested which generated a more substantial flyer plate of aluminum. Low-density polystyrene foam was used as a witness material with subsequent computed tomography analysis to characterize the distribution of particles post-test. Precise digital in-line holography experiments were conducted in situ to measure three-dimensional shape and size of the fastest-moving fragments as they impacted PBXs. Fragments showed significant variability in size, shape and distribution or clustering. Depending on the shot, single or multiple shock impacts could be imparted to the PBX from the generic detonator fragments, or clusters, ranging in size between 100 and 1100 microns and velocities up to 3.5 km/s. The generic detonator fragments were sufficient to initiate PBX 9407 up to 115 mm away, but PBX 9501 was only initiable up to 6 mm. When an RP-80 detonator was used, the more substantial flyer plate initiated PBX 9407 up to 457 mm, while PBX 9501 was only initiable up to 149 mm. This type of data is critical for safety experiments and enables comparison between detonators with different fragment patterns.

We report the results of experiments on the mechanism of function of a commercial detonator based on the exploding bridgewire (EBW) initiation of a low density pellet of the secondary explosive 1,3-propanediol-2,2-bis[(nitrooxy)methyl]-tetranitrate (PETN) coupled to a high density acceptor pellet of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). There is controversy in the literature regarding this mechanism as either a classic shock initiation or initiation by some non-shock (e.g thermal) means. We present time resolved, simultaneous observations of visible light imaging by high speed camera, scattered IR emission, density by x-ray flash radiography, and measurement of propagation velocity during the function of a typical, commercially available RP-80 detonator. We observe a significant delay between the vaporization of the bridge and the initiation of wave motion in the PETN, accompanied by the emission of IR from the initiation location. We do not observe a high density leading edge to the PETN propagation, as we do in subsequent propagation in RDX. We measure propagation velocities expected for detonation in both PETN and RDX at these densities.

The underwater sympathetic detonation of pellet explosives was taken by high-speed photography. The diameter and the thickness of the pellet were 20 and 10 mm, respectively. The experimental system consists of the precise electric detonator, two grams of composition C4 booster and three pellets, and these were set in water tank. High-speed video camera was used with 10 Mfps. The underwater explosion of the C4 booster and a pellet was also taken to estimate the propagation processes of the underwater shock waves. Numerical simulation of the underwater sympathetic detonation of the pellet explosives was also carried out and compared with experiment. The compression process of the pellet caused by interaction of underwater shock wave was clearly taken. Those data could be available to validate the accuracy of reactive flow simulation.

Antropogenic seismicity is one of the most important geomechanical hazard encountered in Polish deep copper mines. Obviously, it may have a negative impact on the peoples safety and the production process. In such circumstances, a number of both active and passive prevention measures have been implemented in the mines, at least partially. One of the most effective, applied for many years, active means used for seismic hazard reduction, is multi-faces blasting works which by assumption should result in release of strain energy accumulated in the rock mass by inducing seismic events in the areas of high strain concentrations. However, at the stage of blasting works design process, a most of attention is paid rather on the vibration amplitude increasing than on the effect of its frequencies. In result, one of the basic parameters of induced seismic waves, which is the frequency of vibrations is usually omitted. Nowadays, the frequency of the seismic wave initiated by firing of group of faces is basically out of control due to the low accuracy of detonators utilized today. Taking the above into account, the possibility of increasing the effectiveness of blasting provocation by controlling the frequency of induced seismic waves was analysed as the effect of the frequencies values assumed to be the dominating ones, around which the computer based 3D FEM solutions of the blasting operation has been simulated.

This paper analyzes the currently available tools for the electrical initiation of industrial explosive charges. The necessity of developing a new generation of special electric detonators is demonstrated. According to the results of theoretical and experimental studies based on the theory of nonlinear multiple resonance processes in complex dynamic systems, a new design of special electric detonators is proposed. The characteristics and results of tests for the developed detonators are shown.

The Rampura Agucha open-pit lead zinc mine is producing 5.7 Mt/a of ore and has started its underground part, which is slated to produce initially 2–2.4 Mt/a and 4.5 Mt/a in the near future. The open-pit mine is currently working at 326 m depth and is designed to reach 421 m deep. It has been planned to operate the underground mine maintaining 50 m parting from the planned ultimate level of the open-pit mine. Presently, open-pit and underground mines are being operated simultaneously. The present average depth of underground working lies between 370 and 410 m below the surface level. Sometimes explosives up to 95,978 kg are being detonated in a blast round in open-pit mine for speedy removal of overburden. The impact of 86 open-pit blasts has been documented in the underground openings and 258 blast vibration data has been recorded. The vibrations were recorded simultaneously in the roof, sidewalls and at floor levels. The highest levels of vibrations were recorded in the roof and the lowest levels at the corresponding floor levels. The pillars experienced lower level of vibrations than those of the roof. Blast designs were optimised at open-pit mine to control vibration in view of long-term safety and stability of the underground openings. The underground development face blasts were also optimised for the safety and stability of underground workings. Vibrations generated due to detonation of explosives with shock tubes and electronic delay detonators have been recorded in underground openings for comparative assessment. Ground vibration recorded at roof, pillar and floor were analysed separately and threshold value of the vibration for the safety of underground workings has been determined based on the Rock Mass Rating of the roof rock and accordingly blast designs have been optimised.

To study the effects of the blast vibration spectrum of the total charges in a hole-by-hole blasting network with surface network detonators, experiments were performed using different charges. The results were analysed based on the peak particle vibration velocity and the response rule of the main vibration frequency using the Hilbert-Huang transform methods. It was concluded that the dominant frequency of the blast vibration is concentrated in the frequency range of 10–50 Hz. With an increase in the total charge, the low frequency components of the blast frequency range of 0–10 Hz gradually increased and the main vibration frequency spectrum tended toward the low frequency region. In addition, the peak particle vibration velocity exhibited an increasing trend. With the increase of distance from the blast centre, the growth speed of the peak particle vibration velocity accelerated with the increase of the total charge.

A comprehensive investigation to determine the initiation power of detonators containing as a base charge the novel explosives: dihydroxylammonium 5,5-bis(tetrazolate-1N-oxide) - TKX-50, dihydroxylammonium 5,5-bis(3-nitro-1,2,4-triazolate-1N-oxide) - MAD-X1, pentaerythritol tetranitrocarbamate - PETNC and 3,3-diamino-4,4-azoxyfurazan - DAAF in comparison with RDX, HMX and PETN was undertaken. In order to estimate the initiation power of the detonators, the underwater initiating capability test was used. The total energy as a sum of the primary shock wave energy and the bubble gas energy was determined for each of these explosives, by measuring the overpressure of the shock waves generated in water. Moreover, the complete synthesis for novel explosives is presented. The thermal behavior of the explosives was investigated using DSC (differential scanning calorimetry). The gas phase absolute molar enthalpies at 298K and 10(5)Pa were calculated theoretically using the modified complete basis set method (CBS-4M;M referring to the use of minimal population localization) with the Gaussian 09 software. Gas phase standard molar enthalpies of formation (H-f degrees((g))) at 298K were computed using the atomization energy method. Standard molar enthalpies of formation (H-(s)degrees) were calculated using H-f degrees((g)) and the standard molar enthalpies of sublimation by applying Trouton's rule. The Chapman-Jouguet (CJ) characteristics based on calculated H-(s)degrees values were computed using the EXPLO5 V6.01 thermochemical computer code. For the calculations the theoretical maximum densities and densities obtained during the experiments presented in this work were used.

Design and experimental study of a detonator using a lengthy exploding wire fuse are proposed. A shock-wave unit using electrically exploding wire for initiating high-explosive charges to create axially symmetric detonation front is developed. The detonators are made and tested in two designs. The design details and the results of experiments are reported.

The stability of pyrotechnic composition used in flame detonator was studied at severe temperatures (–70―130 °C) for 5 d. For single N-LTNR(normal lead styphnate), camera was used to observe the shape and colour of N-LTNR in the DSC(differential scanning calorimetry) furnace during continuous heating and cooling processes. Based on the DSC-TGA(thermogravimetric analysis) results, it can be seen that when the temperature exceeded 110 °C, N-LTNR lost its crystal water, making the energetic material become darker in colour, smaller in dimension, lager in volume and lighter in weight(3.416%); when the temperature was below −40 °C, the phenomenon of sample broking, jumping and cracking happened. For the N-LTNR and Pb(N3)2(lead azide) double layers, the loss of N-LTNR’s crystal water at the temperature higher than 110 °C caused the hydrolysis reaction of Pb(N3)2, and the purity of Pb(N3)2 measured after the temperature cycling decreased from 98.6% to 95.26%. For the flame detonator, the height and diameter of the flame detonator were measured and no apparent changes of them were found. The p-t(pressure-time) test shows that the peak pressure was decreased by 3.9%. Therefore, the operating temperature of this flame detonator should be limited to −40–110 °C.

Dynamic wave interaction and crack propagation in glass have been observed with the edge-on impact (EOI) style test method using an exploding bridged wire (EBW) detonator. The existence of an interlayer or internal surface displayed meaningful wave distortions, delays, reflections, and decreasing amplitude. The interlayer materials used were rubber, stainless steel, and cut surface. The results indicate that the shocks passing the interlayer decrease following the impedance condition and that much of the crack is stopped at the interlayer. The damage pattern was analyzed with the energy and stress dissipation rate.

From the moment that a firing pin triggers the detonator to the moment that a grenade leaves a barrel is called Action Time. Since a loading and percussion of 40mm grenade happens simultaneously, action time should be within a certain time in order to prevent a Jamming malfunction. Previously, unreliable action time device of 40mm grenade made it difficult to improve quality assurance of K4 Grenade Machine Gun. Here, various sensors were compared and a special device was designed to seek an accurate measurement on action time. In this device, the gap between a signal from an optical sensor in Firing Pin and that from Eddy current probe in the barrel was recorded and data were sent to a computer in real time. Confirming if action time is within the criteria, it is expected that action time plays an important role in quality assurance on 40mm grenade.

This paper investigated the damage degree and damage mechanism of aluminum sandwich plate subjected to blast loading by using numerical simulation method. Finite elements models of aluminum foam sandwich plates were established. The distortion and damage pattern of the sandwich plate under different masses of detonator were got by using LS-DYNA to simulate the destructive effect of shock wave and detonation product against sandwich plate. The results showed that the maximal deflection and overloading of the sandwich plates were different because of the changing of mass of detonator. This paper could provide some reference for the designing of sandwich structures.

This study through a new manufacturing process to obtain ultrafine milliseconds, and then test its key performance parameters. Identifying the most important factor affecting the delay precision detonators by orthogonal experiments, thus optimizing formulations to expect to get a better precision detonator recipe. Through the ultrafine particle size of drug testing and the delay in seconds volume testing, analysis presents a method to improve the accuracy of delay detonator, and experimental verification of ultrafine drug delayed by technical feasibility detonator postponed postponed improve accuracy in milliseconds.

This paper presents a comparative investigation of the shock tube and electronic detonating systems practised in bench blasting. The blast trials were conducted on overburden rocks of Garnet Biotite Sillimanite Gneiss formations in one of the largest metalliferous mine of India. The study revealed that the choice of detonating system was crucial in deciding the fragment size and its distribution within the blasted muck-piles. The fragment size and its distribution affected the digging rate of excavators. Also, the shape of the blasted muck-pile was found to be related to the degree of fragmentation. From the present work, it may be inferred that in electronic detonation system, timely release of explosive energy resulted in better overall blasting performance. Hence, the precision in delay time must be considered in designing blast rounds in such overburden rock formations. State-of-art image analysis, GPS based muck-pile profile plotting techniques were rigorously used in the investigation. The study revealed that a mean fragment size (K50) value for shock tube detonated blasts (0.55–0.59 m) was higher than that of electronically detonated blasts (0.43–0.45 m). The digging rate of designated shovels (34 m3) with electronically detonated blasts was consistently more than 5000 t/h, which was almost 13 % higher in comparison to shock tube detonated blasts. Furthermore, favourable muck-pile shapes were witnessed in electronically detonated blasts from the observations made on the dozer performance.

A novel digitally-programmable delay-time microchip is introduced in this paper, which is based on detonating system. In order to make the detonating system more safety and reliability, C-MBUS is proposed in this paper. The programmable delay-time detonator can get power and data from Logger simultaneously. As a conclusion, the programmable delay time of this microchip ranges from 1 millisecond to 10000 milliseconds using the dedicated programming device, and the time programmable increment step can reach 1 millisecond. With its safety and reliability, its accuracy in delay time and its easy use, it will be extensively applicable to complicated blasting engineering of high quality.

Research on the impact of blasting parameters on vibration signals is of significant value for guiding blast-resistant design. Previous research was primarily aimed at the impact on vibration amplitude in the time domain but rarely focused on energy distribution in the frequency domain (i.e., spectrum). Based on large amounts of blast signals from a series of events, in this study, the primary parameters that affect the vibration spectrum were determined. First, the K-means method was used to cluster all of the signals into six distinct spectrum clusters. The T test was then utilized among different clusters, to detect discrepancies in continuous parameters, including total charge, maximum charge, concrete age and distance between the explosion source and measuring point. Meanwhile, a random clustering simulation was conducted to determine whether the other two discrete parameters, i.e., the number of detonator relays and the explosion source location, influence the spectrums of vibration signals. The results show that three of the six parameters studied have a close link to the vibration spectrum, whereas the other three do not. This study also discusses how the parameters impact the occurrence and evolution of vibration signals.

Mixing enhancement in a M=2 crossflow using the transient high-pressure, high-temperature, and high-velocity pulse from a detonation was investigated experimentally. High-frame-rate shadowgraphy and planar laser-induced fluorescence of the nitric oxide molecule showed the structure and time-dependent interaction of the detonation plume with the supersonic flow. The high-momentum flux from the detonation provided significant penetration, with blowdown times of 4–8 ms achieved. Planar laser-induced fluorescence of nitric oxide captured the spanwise structure of the plume and the large counter-rotating vortex structure for enhanced mixing. The upstream jet was shown to be drawn into the pulse detonator’s plume, providing distribution to the core supersonic flow. Significant coupling between a continuous upstream jet and the pulse detonator plume was found and indicated that there was an optimal staging distance for enhanced mixing.