Effects Of Shock Waves Research Articles

Effect of the sonic shock wave on void evolution in materials under irradiation

Understanding the void-cascade interaction is of great importance for clarifying the irradiation damage as a major challenge in nuclear industry, since it typically causes void annihilation or shrinkage, which greatly affects the swelling of irradiated materials. But the current understanding of it is extremely limited due to the neglect of the sonic shock wave. Herein, we take γ-U as the representative model due to the emergence of a violent sonic shock wave there. Molecular dynamics simulations are performed to explore the underlying mechanism of the sonic shock wave interacting with voids. It is firstly revealed that the sonic shock wave is essentially focusons along <111> crystal orientation family, attributed to the highest energy transfer efficiency along <111> in γ-U. These focusons can cause void annihilation or shrinkage via sliding, while thermal spikes only cause annihilation by covering voids. Combining these two factors, we propose a model to qualitatively epitomize the void-cascade interaction, in which the influence scope exhibits an intriguing anisotropic feature, overturning a long-accepted view that the void-cascade interaction is isotropic. This model is further generalized to other nuclear materials owing to the similar mechanism of the sonic shock wave. Moreover, we find distinct size effect of voids on void-cascade interaction. Thermal spikes hardly affect voids that are too large to be covered, while the sonic shock wave also causes visible shrinkage in large voids. The present work proves that the sonic shock wave has a non-negligible effect on void evolution, improving the fundamental understanding of void-cascade interaction in irradiated materials.

The effect of an explosive shock wave on the plate of a protective structure of a critical infrastructure

The article presents the outcomes of an analysis on the stress-strain conditions of reinforced concrete structures subjected to an explosive shock wave resulting from the detonation of a combat unit from a kamikaze drone against a protective screen. When designing protective structures for critical infrastructure, employing computer simulation enables an assessment of the genuine impact of explosive loading on the structural elements' strength. The active phase of explosive loading is exceptionally brief, lasting only a fraction of a second. Under such circumstances, modeling is best performed using explicit methods of direct integration in time.&#x0D; The structure considered in this work is a reinforced concrete slab supported by a metal beam cage with I-beam cross-sections, topped with a sand backfill. The study was executed within the SIMULIA Abaqus software suite, incorporating models depicting nonlinear material behavior in a three-dimensional context. Discretely positioned reinforcement was considered for reinforced concrete structures, and the "Concrete Damage Plasticity" model was applied for concrete, accounting for damage accumulation. The devised computational scheme for the shelter represents a section of the protective structure's roof under conditions of cyclic symmetry.&#x0D; The article elucidates the core principles of incorporating explosive loading according to algorithm CONWEP.The results demonstrate that during the detonation of a kamikaze drone, an explosive wave created a crater in the sand backfill, exposing the slab. The study illustrates the development of damage in the reinforced concrete slab at various time intervals. Despite the identified damage to the slab, the protective structure overall withstood the explosive load. The intensity of the explosive shock wave diminishes significantly as it propagates away from the explosion site.

The fatal effect of shock waves on the head of a person wearing a polyurea-reinforced ballistic helmet

Ballistic helmets are an important part of personal protective equipment in war and are specifically designed to protect a person’s head. The future trend is to improve the protective performance of helmets through the use of lightweight coatings, and polyurea, as one of the hottest elastomeric polymer coating materials in recent years, has excellent physical properties, especially its ability to improve the target’s protection against blast shock waves. Therefore, in this study, using a validated head model, a blast impact model under the fluid-solid coupling method was constructed to study the effect of blast wave on the model and to analyse its effect on intracranial pressure and skull deformation. In addition, the effect of the position of the polyurea lightweight protective coating on the bending deformation of the skull under the effect of the blast wave was also investigated. The results showed that the polyurea coating could reduce the skull deformation under the same surface density condition. However, spraying polyurea on the blast surface of the helmet’s blast-facing surface does not effectively reduce skull deformation caused by blast waves.

The effect of extracorporeal shock wave on joint capsule fibrosis based on A2AR-Nrf2/HO-1 pathway in a rat extending knee immobilization model

Joint capsule fibrosis, a common complication of joint immobilization, is mainly characterized by abnormal collagen deposition. The present study aimed to investigate the effect of extracorporeal shock wave therapy (ESWT) on reduced collagen deposition in the joint capsule during immobilization-induced joint capsule fibrosis. Additionally, the potential involvement of the adenosine A2A receptor (A2AR)-Neurotrophic factor e2-related factor 2 (Nrf2)/Haem oxygenase-1 (HO-1) pathway was explored. Thirty 3-month-old male Sprague–Dawley rats were randomly assigned to five groups: control (C), immobilization model (IM), natural recovery (NR), ESWT intervention (EI), and ESWT combined with A2AR antagonist SCH 58261 intervention (CI). After the left knee joints of rats in the IM, NR, EI and CI groups were immobilized using a full-extension fixation brace for 4 weeks, the EI and CI groups received ESWT twice a week for 4 weeks. The CI group was also treated with ESWT following intraperitoneal injection of SCH 58261 (0.01 mg/kg) for 4 weeks. The range of motion of the left knee joint was measured, and the protein levels of collagens I and III, A2AR, phosphorylated-protein kinase A/protein kinase A (p-PKA/PKA), p-Nrf2/Nrf2, and HO-1 were analysed by Western blotting. The IM and NR groups showed significantly greater arthrogenic contracture than the C group (P < 0.05). Compared to the NR group, the EI and CI groups exhibited significant improvement in arthrogenic contracture (P < 0.05). Conversely, the EI group showed lower contracture than the CI group (P < 0.05). Similar results were observed for collagen deposition and the protein levels of collagens I and III. The intervention groups (EI and CI groups) showed higher levels of p-Nrf2/Nrf2 and HO-1 than the NR group (P < 0.05). Moreover, the EI group exhibited higher levels of p-PKA/PKA, p-Nrf2/Nrf2, and HO-1 than the CI group (P < 0.05). However, no significant difference was found in the A2AR levels among the five groups (P > 0.05). ESWT may activate A2AR, leading to the phosphorylation of PKA. Subsequently, Nrf2 may be activated, resulting in the upregulation of HO-1, which then reduces collagen deposition and alleviates immobilization-induced joint capsule fibrosis.

Shock waves in holographic EPR pair

We study real-time correlators for N = 4 super Yang Mill fields coupled to a pair of entangled quarks using holography, in the setup that energy quanta sent from one quark perturb the quantum state of the fields and affect the other quark. We make the connection with the ER=EPR conjecture by considering the situation when two quarks are uniformly accelerating opposite to each other. The dynamics of quarks, in the gravity dual, is described by the string worldsheet theory, which in this case has the induced metric describing a two-sided AdS black hole, or a wormhole. Energy quanta sent by one of the quarks produce the shock wave on the worldsheet. We find the effect of shock wave on the boundary field correlators and we discuss the consequence for the ER=EPR conjecture.

Acceleration mechanism of abrasive particle in ultrasonic polishing under synergistic physical vibration and cavitation: Numerical study

Ultrasonic technology is widely applied in the engineering ceramic polishing processes without the limitation of material properties and ideally integrated into computer numerical control system. Ultrasonic-induced cavitation and mechanical vibration effect could accelerate the motion of solid abrasives. The individual behaviors of microjet/shockwave of ultrasonic cavitation in gases and liquids, and micro-abrasives with simple harmonic vibrations in solids and liquids has been extensively studied. To conduct a systematic and integrated study of abrasives behavior in the polishing contact region involving abrasive, surround-workpiece wall, ultrasonic physical vibration, and ultrasonic cavitation impact, a novel model integrating the free abrasive motion velocity and fixed abrasive indentation depth under multi-scale contact was proposed according to Hertzian contact theory, Greenwood-Williamson model, indentation deformation theory, the basic equations of cavitation bubble dynamics, cavitation impact control equations, and Newton's law of motion equation. The effects of ultrasonic amplitude, ultrasonic frequency, preloading force and particle size on the proposed model were investigated by theoretical analysis and numerical simulations. Ultrasonic physical vibration mainly influences the dynamic gap and further influence the number of different abrasives. Furthermore, the indentation depth of fixed abrasive depends mainly on the abrasive geometry. As the contact gap and abrasive size decrease, the indentation depth gradually decreases. Under the synergistic effect of cavitation-induced shock wave and microjet, the velocity of free abrasive in this paper is generally 0–150 m/s, and the kinetic energy of free abrasive increases roughly linearly with increasing frequency and approximately as a quadratic function with increasing particle size. Increasing the preloading force leads to a reduction in the abrasive kinetic energy. Besides, the kinetic energy induced by the shock wave has a cliff-like increment at an amplitude of 0.7–0.8 μm. It is revealed that the abrasive kinetic energy is suppressed by the cavitation bubble expansion and collapse at smaller ultrasonic pressure amplitude and surround-wall distance. This research provides a theoretical reference for the modeling of potential defects and material removal on the workpiece surface caused by abrasive motion during polishing, and reduces the trial cost for parameter optimization in actual polishing processing.

The role of the temperature anisotropy in the deuterium-tritium fuel ignition under the effect of relativistic shock waves

The role of the temperature anisotropy in the deuterium-tritium fuel ignition under the effect of relativistic shock waves

Numerical study on atmospheric explosive welding based on the 2D structured arbitrary Lagrangian-Eulerian method

Smooth particle hydrodynamics (SPH) is often adopted to simulate the waveform interface, which has a crucial effect on the bonding quality in explosive welding (EXW). However, owing to the nature of the SPH method, it is difficult to evaluate the influence of the air medium and calculate detailed waveform structure. In this study, a Cu-Q235 steel EXW model containing air medium was established using a structured arbitrary Lagrangian-Eulerian (S-ALE) method. A full-size 2D model was first performed to acquire welding parameters, which were set to the initial conditions for the next oblique collision method. Subsequently, the experiment was conducted to verify the accuracy of the simulations. The results show that the S-ALE method can effectively predict the waveform and acquire the detailed process of the EXW. With the addition of an air medium, the calculated velocity and pressure of the shock wavefront were approximately 3300 m·s−1 and 15 MPa, respectively. Despite the limited effect of the gas shockwave on the overall waveform, the influence on the large-scale or thin plates cannot be ignored. Furthermore, the simulation indicates that the participation of the air during the wave formation led to the generation of the pore in the vortex zone. The proposed method could predict the waveform structure and optimize the manufacturing process of composite plates in the atmospheric EXW.

Examination of the Effects of Dynamic Speed Limit on Shock Waves with a Simulation Technique

The aim of motorway networks is to ensure smooth, high volume road traffic. The problem of anomalies in the system has been a long-standing concern for researchers, and with the widespread use of motorway networks a series of studies have been published on the subject. Speed limitation is one of the most important tools of mitigating disturbances. This study is looking for a solution to the problem known as the "shock wave effect". The research is based on a simulation method in a PTV VISSIM environment. The software can be used to examine certain traffic conditions, and then apply dynamic speed limitation based on these conditions. The Built Environment Information Platform (BENIP) is based on the idea that the built environment, the traffic, and the flow of information between them are closely related. The relevance of the study lies in the fact that a point-based notification of speed limits can be used for vehicles – a technology that is available in most cases at the infrastructure level on motorways – thus, improving road capacity and traffic safety.

Fuel mixing enhancement of transverse coaxial air and fuel jet by upstream shock wave on in scramjet engines: numerical study

In this study, computational fluid dynamics (CFD) is used to disclose the impacts of upstream shock waves on fuel mixing of cross coaxial air and fuel jet at a scramjet engine. This study has tried to investigate the impact of three different lobe injectors (2-lobe, 3-lobe, and 4-lobe nozzle) on the fuel penetrations along the scramjet combustor. The supersonic air stream is M = 4 while cross hydrogen and air jet are released in sonic velocity. This study uses CFD simulations to analyze the effects of upstream shock waves on fuel mixing in the transverse coaxial jet and assess their potential for improving combustion efficiency. The results demonstrate that the usage of upstream shock waves significantly increases shock interactions and augments the vortex region downstream of the jet. Our results show that the impacts of shock waves on the penetration of fuel jet released from the coaxial lobe nozzle are substantial.

New Insights into Flow for a Low-Bypass-Ratio Transonic Fan with Optimized Rotor

In this paper, a three-dimensional aerodynamics optimization system is built and applied to optimize a rotor blade to balance the conflicts between stall margin, total pressure ratio, adiabatic efficiency, and mass flow rate for the high-loading and transonic-flow fan. A novel flow diagnostic method based on vorticity dynamics theory is utilized to analyze the reasons for the improvement in aerodynamic performance in the optimized transonic fan. In the established aerodynamic optimization method, use the blade profile camber line curvature and its leading edge metal angle as the optimization variables, which are optimized by modifying the coordinates of their control points and introducing a genetic algorithm. Finally, the vorticity dynamics parameters, such as the boundary vorticity flux (BVF), azimuthal vorticity and skin-friction lines are used to diagnose the key flow features in the optimized and baseline fan passage. The results indicate that, by controlling skillfully the blade camber line curvature in the optimization improves the aerodynamic performance of the fan stage, increasing the total pressure ratio by 1.90% while increasing the mass flow rate and adiabatic efficiency by 5.82% and 4.45%, respectively. The formulas from the vorticity dynamics diagnosis method indicate a close link between the aerodynamic performance and vorticity dynamic parameters for the axial fan/compressor passage flow, and that both azimuthal vorticity and boundary vorticity flux have significant influence on fan stage performance. Moreover, the boundary layer separation flow on the rotor blade surface is accompanied by a spike of entropy and static pressure, and their derivative/gradient also suffer drastic changes under the effect of shock waves. Detailed flow information can be obtained about the on-wall with high accuracy based on the vorticity dynamics diagnosis method, which provides researchers with a novel method for the turbomachinery aerodynamic design and analysis in the aero-engine engineering development field.

Study on full-coverage film cooling characteristics on turbine vanes under the effect of trailing-edge shock wave

In transonic turbines, the oblique shock wave emanating from the stator's trailing edge impinges on the neighboring suction side, which has a complex effect on boundary layer flow. Numerical studies were performed to investigate the influence of oblique shock wave on suction-side film cooling, and the numerical results were validated by model experiments. The sudden increase of static pressure downstream of shock wave is adverse to coolant outflow, and cooling effectiveness shows a notable drop. Furthermore, injecting coolant into boundary layer can increase kinetic energy, and weaken flow separation caused by shock wave. Detailed influences of geometric and thermodynamic parameters on film cooling performance were analyzed. The increase of pressure ratio causes the downward motion of shock wave, which is beneficial to film cooling. The increase of hole size improves cooling effectiveness before shock wave, but reduces cooling effectiveness after shock wave. Cooling effectiveness decreases as hole inclination angle, hole pitch and spacing increases. Adding hole diameter or reducing hole inclination angle, hole pitch and spacing can increase discharge coefficient. Laminated cooling and film cooling were compared. By introducing jet impingement and pin fins, laminated structures can generate higher cooling effectiveness but lower discharge coefficient.

Physiotherapeutic approaches for the erectile dysfunction management: basic principles and an efficacy evaluation of the current technologies

Physiotherapy is a treatment method for a wide range of diseases of various organs and systems. Its efficacy and practicability are of the great discussions during the past few decades. In urology, this method is used for treatment of erectile dysfunction (ED) caused by a violation of the trophism of genitalia due to radical prostatectomy, atherosclerosis, diabetes mellitus, Peyronie's disease. Shock wave therapy based on the remote action of a low-intensity focused acoustic wave is one of the widely used effective physiotherapeutic methods for the treatment of vasculogenic ED. The main effects of shock waves are neoangiogenesis, nerve fibers regeneration, deceleration of the cavernous fibrosis and reduction of the sympathetic outflow. Some technologies (e.g. radio waves) in addition to those effects also warm the tissues, what accelerates metabolism and improves regenerative processes. All shockwave and radiowave technologies have already demonstrated their efficacy compared with sham control. However, in the few comparative studies, no significant difference was found in efficacy between different technologies. Clinical guidelines consider physiotherapy only as an alternative treatment for patients with mild vasculogenic ED who are refractory or unresponsive to oral vasoactive therapy. Nevertheless, some studies make it possible to judge the efficacy of physiotherapy for treatment of patients with either etiology of the ED. The result of the ED treatment does not depend on the number of treatment courses, their duration, the number of pulses per course and the periodicity of therapy sessions. Also, the original studies have some major shortcomings (i.e. a large percentage of patients dropping out of follow-up). These factors cast doubt on the organotropism of physiotherapy. So, additional comparative studies are required to determine the optimal dosing regimen and to explore the influence of physiotherapy organotropic and psychological components on the results of the treatment. The study aimed to summarize the currently available data evaluating the efficacy of different physiotherapeutic technologies, to compare the efficacy of different technologies for ED treatment.

Preliminary investigation on the effect of extracorporeal shock wave combined with traction on joint contracture based on PTEN-PI3K/AKT pathway.

To investigate the intervention effect of extracorporeal shock wave combined with manual traction on fixation-induced knee contracture and its influence on PTEN-PI3K/AKT signaling pathway. Thirty-six SD male rats were randomly divided into six groups. The left knee joints were not fixed in the control group (C group). Rats in other groups underwent brace fixation in the extended position of the left knee. After 4 weeks of bracing, it is randomly divided into five groups: Model group (M group), natural recovery group (NR group), extracorporeal shock wave treatment group (ET group), manual traction group (MT group), and extracorporeal shock wave combined with manual traction group (CT group). Joint range of motion (ROM) of left knee was carried out to assess joint function. Hematoxylin and eosin (HE) staining and Masson staining were respectively used to assess the cell number and collagen deposition expression. Immunohistochemical staining and Western blot were used to assess protein levels of phosphatase and tensin homolog (PTEN), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (AKT). The combined therapy was more effective than extracorporeal shock wave therapy or manual traction alone against the joint ROM, cell number and the collagen deposition, low-expression of PTEN, and overexpression of PI3K/AKT in the anterior joint capsule of rats with knee extension contracture. Extracorporeal shock wave combined with manual traction can promote the histopathological changes of anterior joint capsule fibrosis, upregulate the protein expression of PTEN and downregulate the protein expression of PI3K/AKT in the fibrotic joint capsule in a rat joint contracture model.

Laminar hypersonic boundary layer flow over planar compression ramp with sharp leading edge and upstream influence

The present work aims to study the effects of shock wave — boundary layer interaction in 2D hypersonic flow at the sharp leading edge of a flat plate and a flat plate followed by a compression ramp. A key parameter in this work is the hypersonic interaction parameter χ, defined as χ≡CM∞3/Re∞1/2. This flow is modeled as a perfect gas and its behavior is studied over various compression ramp configurations, ranging from 0°–6°, using a semi-analytic reduced-order model. In this shock-layer analysis we focus on characterizing the viscous boundary layer for an adiabatic flow over an insulated wall, improving on existing semi-analytic methods by obtaining a non-singular solution, and using the Tangent Wedge approximation to match the pressure on the boundary layer edge. Upstream influence resulting from the compression ramp is also investigated with newly developed correlations.

"Effectiveness of Extracorporeal Shock Wave in Patients with Musculoskeletal Injuries"

"Effectiveness of Extracorporeal Shock Wave in Patients with Musculoskeletal Injuries"

Compare the effectiveness of extracorporeal shockwave and hyperbaric oxygen therapy on enhancing wound healing in a streptozotocin-induced diabetic rodent model.

Studies have revealed that both extracorporeal shock-wave therapy (ESWT) and hyperbaric oxygen therapy (HBOT) can accelerate wound healing. This study aimed to compare the effectiveness of ESWT and HBOT in enhancing diabetic wound healing. A dorsal skin defect in a streptozotocin-induced diabetes rodent model was used. Postoperative wound healing was assessed once every 3 days. Histologic examination was performed with hematoxylin and eosin staining. Proliferation marker protein Ki-67 (Ki-67), endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF), and 8-hydroxy-2-deoxyguanosine (8-OHdG) were evaluated with immunohistochemical (IHC) staining. The wound area was significantly reduced in the ESWT and HBOT groups compared to that in the diabetic controls. However, the wound healing time was significantly increased in the HBOT group compared to the ESWT group. Histological findings showed a statistical increase in neovascularization and suppression of the inflammatory response by both HBOT and ESWT compared to the controls. IHC staining revealed a significant increase in Ki-67, VEGF, and eNOS but suppressed 8-OHdG expression in the ESWT group compared to the HBOT group. ESWT facilitated diabetic wound healing more effectively than HBOT by suppressing the inflammatory response and enhancing cellular proliferation and neovascularization and tissue regeneration.

The Effects of Radial Extra Corporeal Shock Wave and Low-power Laser Therapies on Clinical and Electrophysiological Parameters in Moderate Carpal Tunnel Syndrome: A Blinded Randomized Control Trial

Objectives: Carpal tunnel syndrome (CTS) is a common peripheral entrapment neuropathy with squeezing of the median nerve and the patient is unable to function properly. There are different physiotherapy interventions for the management of these patients and recently, shock wave therapy and low-power laser (LPL) have been widely used, but there is no strong evidence comparing the effect of shock wave therapy and LLLT. Therefore, this trial was designed to compare the effect of extracorporeal shock wave therapy (ESWT), LPL, and routine interventions on clinical outcomes and electrophysiological parameters in patients with moderate CTS. Methods: Fifty-four patients were randomly assigned to the control (routine interventions), ESWT, and LPL therapy groups. All participants received transcutaneous electrical nerve stimulation (TENS) therapeutic ultrasound, hot pack, mobilization, and stretching for ten sessions over two weeks. Additionally, the ESWT group received radial ESWT in four sessions, and the LPL therapy group received laser in ten sessions. The primary outcomes were pain (assessed by the visual analog scale), function (assessed using the Boston questionnaire (BQ)), hand grip, and finger pinch strength. Secondary outcomes were electrophysiological parameters (distal motor and sensory latency and nerve conduction velocity (NCV) of the median nerve. Results: Time group interactions were significant for pain, the symptom severity subscale of BQ, finger pinch, and hand grip strength (p&lt;0.001). Significant improvements were seen in clinical and sensory latency and motor NCV of the median nerve (p&lt;0.05). The ESWT group experienced significant improvements with a large effect size in pain, function, and finger pinch strength compared to the control group (p&lt;0.01). Additionally, the LPL therapy group showed significant changes in the function and finger pinch and hand grip strength compared to the control group. There were no significant differences between the LPL therapy and ESWT groups except for pain in favor of the ESWT group. No significant differences were found among the three groups in electrophysiological parameters (p&gt;0.05). Discussion: Although laser therapy increased the efficacy of routine interventions, it seems adding ESWT to the routine treatment may be superior for the management of moderate CTS patients.

Effect of extracorporeal shock waves on neuromuscular junctions versus carpal tunnel syndrome

Objective:to determine effectiveness of using extracorporeal shockwave therapy (ESWT) directly on the NMJ versus using it on injuries that exert pressure on the nerve such as (CTS). Background: The nervous system can be affected by many conditions and disorders that can disrupt its normal functioning and transmission of impulses, such as the destruction of neuromuscular junctions or pressure on nerves, such as carpal tunnel syndrome. Methods: The review was carried out by searching scientifically recognized medical databases, including PubMed, Scopus, Biomed, National Library of Medicine, Science direct library, Sage Journals and Spinger Link. Date restrictions were not applied. Conclusion: Preliminary research on extracorporeal shockwave therapy for carpal tunnel syndrome has shown encouraging results, leading to recommendations for its potential use as a treatment modality. However, the current literature examining shockwave therapy for neuromuscular junction dysfunction is limited. Further studies through high-quality human trials are still needed.

Effects of controllable shock wave on particle size characteristics of tin polymetallic ore crushing products

Different minerals in tin polymetallic ores have varying degrees of grindability. When the particle size distribution of the crushed ore is unreasonable, sufficient liberation of useful minerals necessitates an increase in the grinding time, resulting in the easily grindable tin metal minerals being over-ground, further causing the loss of tin metal resources in the subsequent beneficiation process. In this study, a controlled shock wave technique based on electrical pulses was introduced to pretreated tin polymetallic ores. The effects on the physical properties of the tin polymetallic ore obtained using controllable shock wave pretreatment were investigated using an ultra-depth three-dimensional microscope, a universal mechanical testing machine, mercury porosimeter, and crushing tests. The crushing results showed that the average particle size of the pretreated ore crushing products was 17.98% smaller than that of the untreated ore crushing products. Furthermore, the particle size characteristic equation demonstrated that the particle size distribution of the pretreated ore crushing products was more reasonable. The mechanism analysis revealed that the internal structure and surface morphology of the tin polymetallic ore were fractured by the controllable shock wave based on the electrical pulse, the compressive strength of the ore after pretreatment was reduced by 91.23%, and the porosity value was increased by 5.38% compared with that of the untreated ore. Therefore, it is feasible to pretreat tin polymetallic ores with controllable shock wave before the crushing process, which reduces the ore crushing resistance and improves the particle size characteristics of ore crushing products.