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Water hammer protection for diversion systems in front of pumps in long-distance water supply projects 被引量:4
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作者 Lin Shi Jian Zhang +3 位作者 Xiao-dong Yu Sheng Chen Wen-long Zhao Xu-yun Chen 《Water Science and Engineering》 EI CAS CSCD 2023年第2期211-218,共8页
For a water supply system with long-distance diversion pipelines, in addition to the water hammer problems that occur beyond pumps, the safety of the water diversion pipeline in front of pumps also deserves attention.... For a water supply system with long-distance diversion pipelines, in addition to the water hammer problems that occur beyond pumps, the safety of the water diversion pipeline in front of pumps also deserves attention. In this study, a water hammer protection scheme combined with an overflow surge tank and a regulating valve was developed. A mathematical model of the overflow surge tank was developed, and an analytical formula for the height of the overflow surge tank was derived. Furthermore, a practical water supply project was used to evaluate the feasibility of the combined protection scheme and analyze the sensitivity of valve regulation rules. The results showed that the combined protection scheme effectively reduced the height of the surge tank, lessened the difficulties related to construction, and reduced the necessary financial investment for the project. The two-stage closing rule articulated as fast first and then slow could minimize the overflow volume of the surge tank when the power failure occurred, while the two-stage opening rule articulated as slow first and then fast could be more conducive to the safety of the water supply system when the pump started up. 展开更多
关键词 Long-distance diversion pipeline Water supply Water hammer Overflow surge tank Regulating valve
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Selection of Hammering Sound Collection Devices for the Development of Total Hip Arthroplasty Support Systems
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作者 Rina Sakai Katsufumi Uchiyama +6 位作者 Shun Nishizawa Tomomi Mizuhashi Takeaki Yamamoto Kazuhiro Yoshida Kensuke Fukushima Naonobu Takahira Masanobu Ujihira 《Journal of Biomedical Science and Engineering》 CAS 2022年第7期179-186,共8页
In total hip arthroplasty, intraoperative femoral fractures can be avoided by analyzing the hammering sounds from the stem inserted into the femur. This procedure is based on a hammering test that makes use of the fac... In total hip arthroplasty, intraoperative femoral fractures can be avoided by analyzing the hammering sounds from the stem inserted into the femur. This procedure is based on a hammering test that makes use of the fact that sound depends on the stability of the object. This technique is generally used in engineering. A system designed to avoid excessive stem hammering by predicting the intraoperative fracture risk based on this technique and software for real-time spectra analysis has been developed with repetitive improvements. The remaining technical challenge lies in selecting an appropriate sound collection device and building a compact and easy unit for use. This study reviewed the types of directional microphones suitable for the sound collection system to develop a practical THA support system. Four types of microphones based on selected methods were used to collect and compare the peak frequencies of the hammering sounds and make comparisons between them, and the built system was used to conduct clinical trials. For miniaturization and operational ease of the unit, plug-in unidirectional microphones are appropriate. However, no laboratory-level data has been collected, and thus, further data accumulation is necessary. 展开更多
关键词 Intraoperative Fractures Total Hip Arthroplasty hammering Sound Fourier Analysis Peak Frequency
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泵站过渡过程计算及水锤防护措施研究
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作者 杨建军 高旭亮 《陕西水利》 2024年第11期101-105,共5页
文章介绍了水锤的基本概念、泵站水锤的危害、水锤防护研究的目的及意义。通过HAMMER软件对实际工程的供水系统进行数字建模,并对事故停泵时水力过渡过程进行模拟计算,对不同防护措施下的计算结果进行对比,最终提出更适合工程的预防水... 文章介绍了水锤的基本概念、泵站水锤的危害、水锤防护研究的目的及意义。通过HAMMER软件对实际工程的供水系统进行数字建模,并对事故停泵时水力过渡过程进行模拟计算,对不同防护措施下的计算结果进行对比,最终提出更适合工程的预防水锤发生的防护措施,从而保证供水系统安全运行,可为类似的工程设计提供参考依据。 展开更多
关键词 泵站 水锤 过渡过程 HAMMER 防护措施
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基于Bently-Hammer软件的长距离输水管道水锤防护模拟 被引量:1
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作者 文思齐 蒋羚鏴 +1 位作者 曾诗 瞿露 《科学技术创新》 2024年第4期110-113,共4页
基于Bently-Hammer软件对某实际工程中长距离输水系统进行建模,通过实际运行中的不同工况,模拟突发事件在管道与水泵间产生的水锤影响,同时针对系统内突发事件增加液压气动罐、缓闭止回阀等水锤消除措施加以改进,为实际工程提供有效抑... 基于Bently-Hammer软件对某实际工程中长距离输水系统进行建模,通过实际运行中的不同工况,模拟突发事件在管道与水泵间产生的水锤影响,同时针对系统内突发事件增加液压气动罐、缓闭止回阀等水锤消除措施加以改进,为实际工程提供有效抑制水锤破坏的技术保障。 展开更多
关键词 长距离输水 水锤防护 水锤计算 Bentley Hammer
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Aseismic performances of constrained damping lining structures made of rubber-sand-concrete
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作者 Xiancheng Mei Qian Sheng +4 位作者 Jian Chen Zhen Cui Jianhe Li Chuanqi Li Daniel Dias 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1522-1537,共16页
Flexible damping technology considering aseismic materials and aseismic structures seems be a good solution for engineering structures.In this study,a constrained damping structure for underground tunnel lining,using ... Flexible damping technology considering aseismic materials and aseismic structures seems be a good solution for engineering structures.In this study,a constrained damping structure for underground tunnel lining,using a rubber-sand-concrete(RSC)as the aseismic material,is proposed.The aseismic performances of constrained damping structure were investigated by a series of hammer impact tests.The damping layer thickness and shape effects on the aseismic performance such as effective duration and acceleration amplitude of time-domain analysis,composite loss factor and damping ratio of the transfer function analysis,and total vibration level of octave spectrum analysis were discussed.The hammer impact tests revealed that the relationship between the aseismic performance and damping layer thickness was not linear,and that the hollow damping layer had a better aseismic performance than the flat damping layer one.The aseismic performances of constrained damping structure under different seismicity magnitudes and geological conditions were investigated.The effects of the peak ground acceleration(PGA)and tunnel overburden depth on the aseismic performances such as the maximum principal stress and equivalent plastic strain(PEEQ)were discussed.The numerical results show the constrained damping structure proposed in this paper has a good aseismic performance,with PGA in the range(0.2-1.2)g and tunnel overburden depth in the range of 0-300 m. 展开更多
关键词 Constrained damping structure Aseismic performance Hammer impact tests Damping layer Peak ground acceleration Overburden depth
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Digital monitoring of rotary-percussive drilling with down-the-hole hammer for profiling weathered granitic ground
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作者 Wendal Victor Yue Siyuan Wu +2 位作者 Manchao He Yafei Qiao Zhongqi Quentin Yue 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1615-1636,共22页
Rock and geotechnical engineering investigations involve drilling holes in ground with or without retrieving soil and rock samples to construct the subsurface ground profile.On the basis of an actual soil nailing dril... Rock and geotechnical engineering investigations involve drilling holes in ground with or without retrieving soil and rock samples to construct the subsurface ground profile.On the basis of an actual soil nailing drilling for a slope stability project in Hong Kong,this paper further develops the drilling process monitoring(DPM)method for digitally profiling the subsurface geomaterials of weathered granitic rocks using a compressed airflow driven percussive-rotary drilling machine with down-the-hole(DTH)hammer.Seven transducers are installed on the drilling machine and record the chuck displacement,DTH rotational speed,and five pressures from five compressed airflows in real-time series.The mechanism and operations of the drilling machine are elaborated in detail,which is essential for understanding and evaluating the drilling data.A MATLAB program is developed to automatically filter the recorded drilling data in time series and classify them into different drilling processes in sub-time series.These processes include penetration,push-in with or without rod,pull-back with or without rod,rod-tightening and rod-untightening.The drilling data are further reconstructed to plot the curve of drill-bit depth versus the net drilling time along each of the six drillholes.Each curve is found to contain multiple linear segments with a constant penetration rate,which implies a zone of homogenous geomaterial with different weathering grades.The effect from fluctuation of the applied pressures is evaluated quantitatively.Detailed analyses are presented for accurately assess and verify the underground profiling and strength in weathered granitic rock,which provided the basis of using DPM method to confidently assess drilling measurements to interpret the subsurface profile in real time. 展开更多
关键词 Drilling process monitoring(DPM) Down-the-hole(DTH)hammer Percussive-rotary drilling Weathering granitic rocks
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基于Bentley Hammer的长距离有压管道输水工程的水锤防护研究
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作者 丁家乐 杨明伟 《河南科技》 2024年第5期32-38,共7页
【目的】在长距离有压管道输水工程中,因管道内部水流条件复杂而容易产生水锤现象,不仅会影响水流正常输送,还可能导致管道破裂。因此,有必要进行长距离有压管道输水工程的水锤防护研究。【方法】基于台前县城乡供水一体化南水北调配套... 【目的】在长距离有压管道输水工程中,因管道内部水流条件复杂而容易产生水锤现象,不仅会影响水流正常输送,还可能导致管道破裂。因此,有必要进行长距离有压管道输水工程的水锤防护研究。【方法】基于台前县城乡供水一体化南水北调配套工程,通过Bentley Hammer软件,在最不利工况下分别建立三种数值模拟模型:无防护措施、加装复合式高速进排气阀水锤防护、气囊式空气罐和复合式高速进排气阀,进行联合水锤防护,对以上三种情况进行水力过渡过程数值模拟分析,研究复合式高速进排气阀与气囊式空气罐联合防护时的水锤防护效果以及气囊式空气罐的防护能力与预设压力和罐体体积之间的关系。【结果】结果表明:复合式高速进排气阀和气囊式空气罐可以很好地消除管道内水锤带来的危害,气囊式空气罐防护能力随着罐体体积和预设压力的增大而增强,罐体体积对其防护能力影响更显著。【结论】选择合理的罐体体积和预设压力可以使水锺防护发挥最好的防护效果,最大化输水工程的经济性。 展开更多
关键词 水锤 水锤防护 复合式高速进排气阀 气囊式空气罐 Bentley Hammer
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基于BentleyHammer的长距离压力输水管道水锤模拟分析
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作者 关祥飞 《中文科技期刊数据库(全文版)工程技术》 2024年第5期0163-0167,共5页
水锤模拟分析在保证工程安全运行、减少事故发生、降低人身财产风险损失等方面具有十分重要的意义。本文利用Bentley Hammer水锤分析软件,以某县城工业园区供水工程为例,模拟长距离压力输水管道工程非正常运行条件下管道水力工况,分析... 水锤模拟分析在保证工程安全运行、减少事故发生、降低人身财产风险损失等方面具有十分重要的意义。本文利用Bentley Hammer水锤分析软件,以某县城工业园区供水工程为例,模拟长距离压力输水管道工程非正常运行条件下管道水力工况,分析制定安全可靠、合理可行的水锤防护方案,保证供水工程运行安全,为长距离压力输水管道工程水锤防护方案的设计提供参考。 展开更多
关键词 BENTLEY Hammer软件 长距离输水 水锤防护。
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Bentley Hammer V8i软件在城乡一体化供水管道水锤计算中的应用
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作者 宋刚 王金茂 《吉林水利》 2024年第1期42-45,共4页
应用Bentley Hammer V8i软件模拟城乡统筹供水工程中输水和配水管道的稳态工况与事故断电工况的水锤安全性,可以清楚地展示管内水流压力的变化趋势。本文以新和县城乡一体化实际供水工程为研究对象,评估其供水管网水锤安全性。模拟结果... 应用Bentley Hammer V8i软件模拟城乡统筹供水工程中输水和配水管道的稳态工况与事故断电工况的水锤安全性,可以清楚地展示管内水流压力的变化趋势。本文以新和县城乡一体化实际供水工程为研究对象,评估其供水管网水锤安全性。模拟结果显示,虽然该工程在稳态工况与事故断电情况下管道内压力会有剧烈波动,但仍在管道的承载能力之内,可以通过优化关阀时间及相关操作来确保供水的安全稳定。本应用可供类似城乡一体化供水工程管道设计参考。 展开更多
关键词 Bentley Hammer V8i软件 城乡一体化供水 水锤
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RESEARCH OF THE DYNAMIC CHARACTERISTICS ON A NEW HYDRAULIC SYSTEM OF ELECTRO-HYDRAULIC HAMMER 被引量:9
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作者 Li Yongtang Lei Bufang Department of Mechanical Engineering,Taiyuan Heavy Machinery Institute Shi Enxiu Xi’an University of Science and Technology 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2001年第2期171-174,共4页
A new typed hydraulic system of electro hydraulic hammer is researched and developed By means of power bond graphs the modeling and simulation to the dynamic characteristics of the new hydraulic system are performed... A new typed hydraulic system of electro hydraulic hammer is researched and developed By means of power bond graphs the modeling and simulation to the dynamic characteristics of the new hydraulic system are performed The experimental research which is emphasized on the blowing stroke is also performed It is proved from the result of simulation and experiment that this new hydraulic system possesses such advantages as simplification of structure,flexibleness of operation and reliability of working Especially it possesses better dynamic characteristics 展开更多
关键词 ELECTRO hydraulic hammer Hydraulic system Dynamic characteristics SIMULATION
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Usefulness of Hammering Sound Frequency Analysis as an Evaluation Method for the Prevention of Trouble during Hip Replacement 被引量:5
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作者 R. Sakai K. Uchiyama +4 位作者 N. Takahira M. Kakeshita Y. Otsu K. Yoshida M. Ujihira 《Journal of Biomedical Science and Engineering》 2020年第5期74-80,共7页
In total hip arthroplasty, judgment of the appropriateness of stem hammering is dependent on the experience and feelings of the surgeon and no objective evaluation method has been established. In this study, a frequen... In total hip arthroplasty, judgment of the appropriateness of stem hammering is dependent on the experience and feelings of the surgeon and no objective evaluation method has been established. In this study, a frequency analysis of the hammering sounds in total hip arthroplasty was performed to investigate objective judgment criteria capable of preventing problems during surgery. Stem hammering was applied following the surgeon’s feelings as usual in an operating room. A directional microphone was placed at a distance about 2 m from the surgical field and the peak frequency reaching the maximum amplitude was determined by Fourier analysis. It was clarified that the same peak frequency repeats when appropriate fixation is acquired during surgery, suggesting that intraoperative fracture and postoperative loosening can be prevented by stopping hammering at the time the peak frequency converged. Investigation of changes in the hammering sound frequency may serve as objective judgment criteria capable of preventing problems during surgery. 展开更多
关键词 HIP Replacement Total HIP ARTHROPLASTY hammering SOUND Frequency Analysis Intraoperative Fracture LOOSENING
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Prediction of Intraoperative Fracture by Hammering Sound Frequency Analysis and Stress Estimation during Total Hip Arthroplasty 被引量:4
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作者 Rina Sakai Takeaki Yamamoto +4 位作者 Katsufumi Uchiyama Kensuke Fukushima Naonobu Takahira Kazuhiro Yoshida Masanobu Ujihira 《Journal of Biomedical Science and Engineering》 2020年第6期113-119,共7页
When a stem is inserted into the femur during total hip arthroplasty, sufficient fixation depends on the surgeon’s experience. An objective method of evaluating whether the stem has been correctly fixed may aid clini... When a stem is inserted into the femur during total hip arthroplasty, sufficient fixation depends on the surgeon’s experience. An objective method of evaluating whether the stem has been correctly fixed may aid clinicians in their decision. We examined the relationship between the sound frequency caused by hammering the stem and the internal stress in artificial femurs, and evaluated the utility of sound frequency analysis to prevent intraoperative fracture. Surgeons inserted one of two types of cementless stems (SL-PLUS and modified CLS) using routine operational procedures into 13 artificial femurs. These are the standard Zweymüllers used in Europe. The difference is the lateral shape;SL-PLUS has holes for removal and the modified CLS has fins to prevent rotation. We estimated stress in the femur via finite element analysis, measured the hammering force, and recorded the sound of hammering for frequency analysis. Finite element analysis revealed that the hammering sound frequency decreased as the maximum stress increased. A decrease in frequency suggested that fixation was sufficient and that continued hammering would increase the risk of fracture. Thus, evaluation of the change in sound frequency during stem insertion may indicate when the hammering force should be reduced, thereby preventing intraoperative periprosthetic fractures. Further frequency change may also predict fractures prior to visual confirmation. We concluded that sound frequency analysis has potential as an objective evaluation method to help prevent intraoperative periprosthetic fractures during stem insertion. 展开更多
关键词 Periprosthetic Fracture Total Hip Arthroplasty hammering Sound Frequency Analysis
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Numerical Calculation of Artillery-Fuze System Dynamic Characteristics 被引量:1
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作者 王亚斌 刘明杰 谭惠民 《Journal of Beijing Institute of Technology》 EI CAS 2007年第4期384-387,共4页
A numerical calculation method based on the finite element analysis of dynamic characteristics of artillery-fuze system is discussed in detail. Pretension element is used to mesh the couple structure between artillery... A numerical calculation method based on the finite element analysis of dynamic characteristics of artillery-fuze system is discussed in detail. Pretension element is used to mesh the couple structure between artillery and fuze to analyze the change of dynamic characteristics of artillery-fuze system when pre-tightening force varies between artillery and fuze. Numerical calculation of the finite element analysis and actual hammering test of a artillery-fuze system are carried out with the same input to verify the accuracy of numerical calculation. The results show that the finite element model of artillery-fuze system is credible and the calculation accuracy is perfect. 展开更多
关键词 artillery-fuze system finite element analysis hammering test
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Hammering Sound Frequency Analysis to Fix an Acetabular Cup during Total Hip Arthroplasty: Clinical Trials and Biomechanical Studies 被引量:2
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作者 Rina Sakai Katsufumi Uchiyama +3 位作者 Kensuke Fukushima Naonobu Takahira Kazihiro Yoshida Masanobu Ujihira 《Journal of Biomedical Science and Engineering》 2021年第1期14-20,共7页
Failure during total hip arthroplasty may lead to bedridden of the elderly. Since the acetabulum cup fix in an anatomically deep region, failures, such as loosening and fracture, occur three times more frequently comp... Failure during total hip arthroplasty may lead to bedridden of the elderly. Since the acetabulum cup fix in an anatomically deep region, failures, such as loosening and fracture, occur three times more frequently compared with failures of the stem fix in the femur. We investigated the possibility of evaluating whether fixation was acquired by frequency analysis of the hammering sound of implanting a cup into the acetabulum. The subjects were 11 patients (11 joints) who underwent total hip arthroplasty, biomechanical test materials, and orthopedic models. Surgeries and experiments were performed by orthopedists specialized in the hip. A system was constructed with a tablet PC and directional microphone, the peak frequency at which the amplitude reached the maximum was determined, and judgment processing (stable, unstable) of cup fixability was performed in real time. The stable maximum peak frequency observed in the clinical trials was 4.42 ± 4.02 kHz. The mean stable maximum peak frequency in the biomechanical tests was 4.46 ± 1.19 kHz in biomechanical test materials and 4.56 ± 2.02 kHz in orthopaedicmodels. When hammering was continued, the frequency leading to fracture decreased in both biomechanical test materials and orthopaedicmodels. In conclusion, in clinical trials and biomechanical studies, variation of the maximum peak frequency decreased when fixation was acquired and the frequency stabilized. It was suggested that this method can serve as a fixability evaluation method of acetabular cups because analysis can be performed in real time during surgery, for which prevention of intraoperative fracture can be expected. 展开更多
关键词 Total Hip Arthroplasty hammering Sound Frequency Analysis Intraoperative Fracture LOOSENING
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Flux Vector Splitting Schemes for Water Hammer Flows in Pumping Supply Systems with Air Vessels 被引量:1
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作者 Qiang Sun Yuebin Wu +1 位作者 Ying Xu Tae Uk Jang 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2015年第3期69-74,共6页
To solve water hammer problems in pipeline systems,many numerical simulation approaches have been developed. This paper improves a flux vector splitting( FVS) scheme whose grid is the same as the fixedgrid MOC scheme.... To solve water hammer problems in pipeline systems,many numerical simulation approaches have been developed. This paper improves a flux vector splitting( FVS) scheme whose grid is the same as the fixedgrid MOC scheme. The proposed FVS scheme is used to analyze water hammer problems caused by a pump abrupt shutdown in a pumping system with an air vessel. This paper also proposes a pump-valve-vessel model combining a pump-valve model with an air vessel model. The results show that the data obtained by the FVS scheme are similar to the ones obtained by the fixed-grid method of characteristics( MOC). And the results using the pump-valve-vessel model are almost the same as the ones using both the pump-valve model and the air vessel model. Therefore,it is effective that the proposed FVS scheme is used to solve water hammer problems and the pump-valve-vessel model replaces both the pump-valve model and the air vessel model to simulate water hammer flows in the pumping system with the air vessel. 展开更多
关键词 water hammer method of characteristics flux vector splitting air vessel
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Investigation of Hammering Sound Frequency to Prevent Intraoperative Fracture during Total Hip Arthroplasty 被引量:2
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作者 Rina Sakai Tatsuki Kitazato +4 位作者 Katsufumi Uchiyama Kazuhiro Yoshida Takeaki Yamamoto Naonobu Takahira Masanobu Ujihira 《Journal of Biomedical Science and Engineering》 2021年第10期339-345,共7页
<strong>Background: </strong>The 1st peak frequency of the hammering sound in total hip arthroplasty may serve as an evaluation index to prevent intraoperative fracture. Fixation of the stem and femur cann... <strong>Background: </strong>The 1st peak frequency of the hammering sound in total hip arthroplasty may serve as an evaluation index to prevent intraoperative fracture. Fixation of the stem and femur cannot be acquired unless the 1st peak frequency of hammering the stem into the femur stabilizes, and fixation can be judged as acquired when the 1st peak frequency becomes constant. To investigate whether the environmental sound in the operating room can be differentiated from the hammering sound of total hip arthroplasty, the 1st peak frequency of the hammering sound when impacting the stem into the femur with a hammer was identified. <strong>Method:</strong> The hammering sound of impacting the stem into a biomechanical test material through an impactor was analyzed using a fast Fourier transform analyzer. Environmental sound in the operating room was simulated and the 1st peak frequency of the sound on collision between the operator’s voice and the surgical instrument was measured. The 1st peak frequency of hammering sound was compared between patients indicated for total hip arthroplasty and healthy individuals to investigate whether there is a difference due to bone quality. <strong>Results:</strong> The natural frequency of the impactor was 3.41 ± 0.05 kHz, and the 1st peak frequency of the femur, stem, and impactor was 2.43 ± 1.45 kHz. The 1st peak frequency of hammering sound on simulated femur in patients indicated for total hip arthroplasty was 2.98 ± 0.73 kHz and that in healthy individuals was 2.15 ± 0.32 kHz. This suggested that the hammering sound in total hip arthroplasty-indicated patients overlaps with the frequency of the collision sound of surgical instruments.<strong> Conclusion: </strong>To develop a system to prevent intraoperative fracture, countermeasures, such as noise canceling, are necessary to prevent false detection of hammering sounds. 展开更多
关键词 Total Hip Arthroplasty Periprosthetic Fracture Cementless Stem hammering Sound Peak Frequency
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FGC-15D large-diameter DTH air hammer drilling system and its application in offshore rock-socketed pile hole drilling 被引量:3
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作者 Kun YIN Jianming PENG Maosen WANG Zhanjiang ZHOU 《Global Geology》 2006年第2期138-140,共3页
In the past two decades, numerous large-diameter rock-socketed piles were constructed in China to support foundations of skyscrapers, great bridges or to retain soil in potential geological hazard areas. However, dril... In the past two decades, numerous large-diameter rock-socketed piles were constructed in China to support foundations of skyscrapers, great bridges or to retain soil in potential geological hazard areas. However, drilling large-diameter rock-socketed pile holes with conventional drilling method such as rotary drilling or cable tool drilling is time-consuming and the cost is usually very high. In order to drill large-diameter rocksocketed pile holes faster at relatively low cost, the FGC15A large-diameter DTH air hammer drilling system was developed in 1987 and was given the second-clasa award by Ministry of Geology and Mineral Resources in 1991. Since it was innovated the drilling system has been used in more than twenty important and tough pro- jects on land, and wonderful results were acquired. At the same time the large-diameter DTH air hammer drilling system was improved continuously. The FGC15D is the latest version of the technique. 展开更多
关键词 DTH air hammer drilling system pile hole drilling
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Numerical solution for dynamics of pneumatic DTH hammer system 被引量:2
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作者 QU Yegao,BU Changgen,LIU Baolin,Lian Yinjun(China University of Geosciences,Beijing 100083,China) 《探矿工程(岩土钻掘工程)》 2009年第S1期170-176,共7页
The pneumatic down-the-hole(DTH) hammer is one of the efficient equipments used in medium hard to very hard rock drilling frield,and any change in its structure design affects all performance parameters of a pneuamtic... The pneumatic down-the-hole(DTH) hammer is one of the efficient equipments used in medium hard to very hard rock drilling frield,and any change in its structure design affects all performance parameters of a pneuamtic DTH hammer directly.Yet,owing to the complexity of the dynamic interaction among the components in DTH hammer systems,until now it has been difficult to obtain reliable estimates of the design parameter affects.Thus providing an design parameter optimization and the layout of dynamics behavior of DTH hammer is of great importance.This paper documents the development and solution of a computational model for the dynamic response of a pneumatic DTH hammer.The model consists of rigid piston dynamics equation and chamber thermodynamics equations.The resulting model represented by a set of coupled nonlinear differential equations were computed in Visual C++ program.The developed solutions are used to perform a parametric study to illustrate the inffluence of the piston mass and supply pressure on the impact performance of DTH hammer system. 展开更多
关键词 simulation Impact down-the-hole(DTH) HAMMER
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Factors Influence on the Broaching Hammering Sound during Cementless Total Hip Arthroplasty 被引量:1
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作者 Xu Zhuang Yasuhiro Homma +5 位作者 Taichi Sato Tomonori Baba Itaru Morohashi Hideaki Iwase Kazuo Kaneko Muneaki Ishijima 《Journal of Biomedical Science and Engineering》 CAS 2022年第9期229-240,共12页
Background: The aim of this study is to identify the factors influence on the broaching hammering sound character during cementless total hip arthroplasty. Methods: We analyzed frequency spectrum of the hammering soun... Background: The aim of this study is to identify the factors influence on the broaching hammering sound character during cementless total hip arthroplasty. Methods: We analyzed frequency spectrum of the hammering sound for 49 cases of uncomplicated cementless THAs using two types of proximal-coated stem performed by experienced surgeons. Normalized sound pressure (NSP) of each 0.5 kHz frequency band in final stage of broach procedure was determined by the fast Fourier transform analysis. The relationships between those sound characteristics and femoral morphology such as canal calcar ratio (CCR), Canal flare index (CFI), morphological cortical index (MCI) and femoral shaft length (FSL) in different cementless stem were investigated. Results: In Accolade 2, CCR was positively related to NSP in several bands [Frequency band (kHz);r: 2.0 - 2.5;0.37, 4.5 - 5.0;0.37, 9.5 - 10.0;0.44], and negatively related to 7.5 - 8.0 kHz (r = -0.39). Negative correlations were observed among CFI and MCI in specific frequency bands (4.5 - 5.0, 5.0 - 5.5, and 7.5 - 8.0 kHz). In Taperloc Microplasty, strong correlations were found between FSL and the NSP of 7.5. - 8.0 kHz (r = 0.78) and CCR and the 7.5 - 8.0 kHz bands. There was significant difference of NSPs between high and low group divided by morphological parameters. Acoustic characteristics of NSPs between Accolade 2 and Microplasty were significantly different in 9 frequency bands. Conclusions: The hammering sound correlated with four parameters of the femoral morphology and differed in different types of proximal-coated stem. Those novel five factors are important to consider when to predict complications using acoustic analysis. 展开更多
关键词 Total Hip Arthroplasty Cementless Stem hammering Sound Fast Fourier Transform Femoral Morphology
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Structure Parameters Optimization Analysis of Hydraulic Hammer System 被引量:1
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作者 Guoping Yang Jian Fang 《Modern Mechanical Engineering》 2012年第4期137-142,共6页
In order to improve the impact performance, the structure of hydraulic hammer should be optimized. In this paper, the ranges of eight vital structure parameters of piston and reversing valve system of hydraulic hammer... In order to improve the impact performance, the structure of hydraulic hammer should be optimized. In this paper, the ranges of eight vital structure parameters of piston and reversing valve system of hydraulic hammer were selected firstly;and then found the best value of different parameters under experiments with the method of computer optimization and the parametric analysis method provided by ADAMS software. These methods worked and the best design values of parameters of hydraulic hammer were obtained. At last, the optimal impact energy of virtual prototype of hydraulic breaking hammer was calculated and compared with the original impact performance. The results reveal that impact performance of hydraulic hammer has been improved significantly. 展开更多
关键词 HYDRAULIC HAMMER STRUCTURE PARAMETERS Optimization Analysis IMPACT Performance ADAMS
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