scholarly journals Experimental Study on the Damage Characteristics of Polymer Slabs Subjected to Air Contact and Close-In Explosions

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Zhidong Liu ◽  
Xiaohua Zhao ◽  
Hongyuan Fang ◽  
Xueming Du ◽  
Binghan Xue ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shock Wave ◽  
Failure Mode ◽  
Explosive Charge ◽  
Time History ◽  
Dynamic Mechanical Properties ◽  
Charge Weight ◽  
Pressure Time ◽  
Static Mechanical ◽  
Air Explosion

As a new antiseepage reinforcement material, polyurethane grouting material has been widely studied in terms of its static mechanical properties. However, research on its dynamic mechanical properties is relatively rare. In this research, considering the influence of the explosive charge weight, the air contact and close-in explosion experiments of polymer slabs were carried out. The failure mode and damage spatial distribution characteristics of polymer slabs were explored. Pressure time history curve of air shock wave was obtained using an air shock wave tester. The influence of polymer slabs on the propagation of air explosion shock wave was compared and analyzed. The results show that, under the air contact explosion, the polymer slab mainly suffers local damage, while under close-in explosion, overall damage is the main damage mode. With the increase of the explosive charge weight, the failure mode of the polymer slab transits from surface crack and slight spalling to local and whole crushing.

EFFECT OF CARBON BLACK NATURE ON DYNAMIC MECHANICAL PROPERTIES AND REINFORCEMENT OF NR VULCANIZATION BY LATEX TECHNIQUES

2017 ◽  
Vol 90 (4) ◽  
pp. 611-620
Author(s):  
An Dong ◽  
Zhang Zhiyi ◽  
Jia Haixiang ◽  
Shou Jinquan ◽  
Zhang Huan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
Dynamic Mechanical Properties ◽  
Mixing Process ◽  
Scanning Electron Micrograph ◽  
Dynamic Mechanical ◽  
Unit Operations ◽  
New Process ◽  
Static Mechanical ◽  
Filler Dispersion

ABSTRACT The influence of the structure and size of carbon black on the static mechanical and dynamic mechanical properties of filled natural rubber (NR) compounds is investigated in detail. A new process for the production of carbon black master batches with enhanced mechanical properties has been developed. The unit operations in the process are the preparation of carbon black slurry in the presence of a suitable surfactant, addition of the slurry to the fresh NR latex under stirring, coagulation of the mixture by the addition of acid, dewatering of the coagulum, and drying to obtain carbon black–incorporated NR. The competence of the new technique is established by comparing the characteristics of the carbon black–incorporated NR by the mill mixing process (control). The mechanical properties, including tensile strength, modulus, tear strength, and hardness, are superior for the vulcanization prepared by the latex-suspension coagulation techniques. The improvement shown by the vulcanization prepared by the latex-suspension coagulation techniques was attributed to the better filler dispersion evidenced from the scanning electron micrograph along with the attainment of a higher level of vulcanization.

Destruction of Cryogenic Pressure Vessel and Piping by Shock Wave

2005 ◽  
Author(s):  
Toshiaki Watanabe ◽  
Kazumasa Ebihara ◽  
Kazuyuki Hokamoto ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Pressure Vessel ◽  
Industrial Development ◽  
Pressure Rise ◽  
Time History ◽  
Cryogenic Fluids ◽  
Inner Pressure ◽  
Pressure Time ◽  
Medical Facilities ◽  
Lng Tank

In recent years, a use for cryogenic fluids as a coolant has been increasing because of the industrial development of low temperature technology. Therefore, the use of the cryogenic pressure vessel and piping become general. LNG-tank, LN2, O2-tank at food factory and medical facilities are given for example. In the cryogenic pressure vessel and piping, reducing the thermal insulation of that by initial small damage, leads to an internal pressure rise and occurring of flashing, and causing secondary crush of pressure vessel and piping also. Then, we conducted the experiment, which imitates crush when the pressure vessel and piping, which were filled with cryogenic temperature fluid, receive a shock wave. The inner pressure time history in such as this situation was measured, and safety of cryogenic pressure vessel and piping was considered.

The Optimized Design of Manufacturing Process of Shrub Scrimber

2013 ◽  
Vol 712-715 ◽  
pp. 597-600
Author(s):  
Yan Fang Li ◽  
Ying Cheng Hu ◽  
Li Zhang ◽  
Jia Yao ◽  
Jie Yuan
Keyword(s):  
Mechanical Properties ◽  
Manufacturing Process ◽  
Orthogonal Experiment ◽  
Flexural Vibration ◽  
Dynamic Mechanical Properties ◽  
Optimized Design ◽  
Static Mechanical ◽  
Flexural Vibration Test ◽  
Natural Wood ◽  
Nondestructive Testing Method

In this study, the optimized manufacturing process of Shrub Scrimber has been researched by using orthogonal experiment. The dynamic mechanical properties of Shrub Scrimber were measured by Fast Fourier Transform (FFT) nondestructive testing method, and the reliability of this method was verified by the linear regression between the static mechanical properties and the dynamic one. The results showed that shrub Scrimber had excellent mechanical properties, and can be used as structure replaced natural wood. The flexural vibration test were confirmed reliable to predict the mechanical properties of Shrub Scrimber.

Destruction of Cryogenic Pressure Vessel and Piping by Shock Wave

2006 ◽  
Vol 129 (1) ◽  
pp. 38-42
Author(s):  
Toshiaki Watanabe ◽  
Kazuyuki Hokamoto ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
Food Processing ◽  
Pressure Rise ◽  
Time History ◽  
Industrial Applications ◽  
Cryogenic Fluids ◽  
Pressure Time ◽  
Lng Tank

In recent years, the usage of cryogenic fluids as coolant are gaining more attention due to their capability to fulfill the requirements of today’s advancing low temperature industrial applications. As a result, the use of a cryogenic pressure vessel and piping in LNG-tank, LN2, O2 tank for food processing applications and medical applications are becoming more important. In a cryogenic pressure vessel and piping, the reduction of thermal insulation by a small initial damage leads to an internal pressure rise and occurrence of flashing, which leads to a secondary crush of the vessel. In this study, a shock wave was applied to a pressure vessel and piping filled with cryogenic fluid and various observations were made. The internal pressure time history was measured and the safety of the cryogenic pressure vessel and piping was considered.

scholarly journals Numerical Approximation of Blast Loads on Confined Dry-Stacked Masonry Wall

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Muhammad Ishfaq ◽  
Azmat Ullah ◽  
Awais Ahmed ◽  
Sarfraz Ali ◽  
Syed Muhmmad Ali ◽  
...  
Keyword(s):  
Numerical Model ◽  
Time History ◽  
Experimental Tests ◽  
Masonry Wall ◽  
Experimental Results ◽  
Charge Weight ◽  
Test Cases ◽  
Pressure Time ◽  
Out Of Plane ◽  
A Charge

This research intends to numerically study the out-of-plane behaviour of confined dry-stacked masonry (CDSM) walls against blast loading. CDSM is a mortarless interlocking masonry system consisting of Hydraform blocks laid in stretcher bond with reinforced concrete (RC) confining elements. A nonlinear numerical model is developed using advanced finite element hydrocode ANSYS-Autodyn to study the response of CDSM walls subjected to explosive loads. Four different test cases using a charge weight of 4 kg, 8 kg, 12 kg, and 16 kg of Wabox explosive are investigated numerically. The results obtained from numerical simulation are validated with the experimental tests results. The numerical results are found in good agreement with the experimental results. The ability of the numerical model is studied to correctly predict the pressure-time history in pressure gauges installed on walls and compared with experimental data. Peak incident overpressures obtained in these numerical tests ranged from 240 to 1000 kPa. Likewise, the damage patterns obtained from the numerical simulations are compared with available experimental results which show a satisfactory agreement. This study helps to check the response of CDSM structures against blast load which can be used for the construction of blast resisting design of buildings.

scholarly journals Investigation of the Propagation Characteristics of Underwater Shock Waves in Underwater Drilling Blasting

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xin Liu ◽  
Wenbin Gu ◽  
Jianqing Liu ◽  
Zhenxiong Wang ◽  
Jinglin Xu ◽  
...  
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Linear Regression Analysis ◽  
Time History ◽  
Engineering Practice ◽  
Underwater Shock Wave ◽  
Pressure Time ◽  
Underwater Shock ◽  
Measured Pressure ◽  
Fitting Model

During the first-stage project of the main channel of Ningbo-Zhoushan Port’s Shipu Harbor, underwater shock waves were monitored. By analyzing a typical measured pressure time history curve, the characteristics of underwater shock waves in an engineering context were obtained. We obtained a traditional exponential attenuation formula for underwater shock waves based on the measured data, simplified the model of underwater drilling blasting based on engineering practice, deduced a revised formula for underwater shock wave peak overpressure on the basis of dimensional analysis, established a linear fitting model, and obtained the undetermined coefficients of the revised formula using a linear regression analysis. In addition, the accuracies of the two formulas used to predict underwater shock wave peak overpressure and the significance order of influence and influence mechanism of factors included in the revised formula on the underwater shock wave peak overpressure were discussed.

The Effect of Heat Treatment on Static and Dynamic Mechanical Properties of Rapidly Solidified and Plastically Consolidated RS442 Aluminium Alloy

2015 ◽  
Vol 641 ◽  
pp. 17-23
Author(s):  
Maciej Motyka ◽  
Tomasz Tokarski ◽  
Waldemar Ziaja ◽  
Mateusz Wedrychowicz
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminium Alloy ◽  
Bending Strength ◽  
Fatigue Behaviour ◽  
Extrusion Process ◽  
Dynamic Mechanical Properties ◽  
Static Mechanical ◽  
Rapidly Solidified ◽  
Static Mechanical Properties

Ultra-fine grained metallic materials are characterized by higher mechanical properties comparing with their conventional equivalents. However increase in strength under static load is not always accompanied by improved fatigue behaviour. Previous investigations on submicrocrystalline RS442 aluminium alloy produced by plastic consolidation of rapidly solidified flakes in the extrusion process revealed increase in its high cycle fatigue bending strength caused by annealing at 450°C. The aim of present studies was to evaluate the influence of heat treatment – also precipitation hardening – on static mechanical properties (hardness, tensile and yield strength) and fatigue strength of the alloy determined in high cycle stress controlled bending tests. Correlation between microstructure, static mechanical properties and fatigue behaviour was analyzed too.

Effect of Sisal Fibre Hybridisation on Static and Dynamic Mechanical Properties of Corn/Sisal/Polylactide Composites

2017 ◽  
Vol 25 (6) ◽  
pp. 463-470 ◽  
Author(s):  
Honglin Luo ◽  
Dehui Ji ◽  
Guangyao Xiong ◽  
Lingling Xiong ◽  
Chuanyin Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hybrid Composites ◽  
Dynamic Mechanical Properties ◽  
Peak Height ◽  
Sisal Fibre ◽  
Dynamic Mechanical ◽  
Static Mechanical ◽  
Tan Δ ◽  
First Time ◽  
Static Mechanical Properties

The relatively poor mechanical properties of corn fibre (CF) and its green composites have hindered its applications. In this work, sisal fibre (SF) was hybridised with CF to reinforce polylactide (PLA) composites (CF/SF/PLA). The static mechanical properties such as tensile, flexural and impact strengths and dynamic mechanical properties such as storage modulus (E’), damping behaviour (tan δ), glass transition temperature (Tg) of the hybrid composites were determined and, for the first time, hybrid effects on both static and dynamic mechanical properties were evaluated. It is found that the tensile, flexural, impact strengths, and E’ and tan δ peak height, as well as the hybrid effects change with hybrid ratio (SF:CF). It is demonstrated that a hybrid composite with desirable static and dynamic mechanical properties can be produced by optimising the fibre:hybrid ratio.

Study on Mechanical Properties of Self-Piercing Riveted Joints about Titanium Alloy

2015 ◽  
Vol 723 ◽  
pp. 856-859 ◽  
Author(s):  
Yi Lu ◽  
Xiao Cong He ◽  
Yi Feng Wang
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Failure Mode ◽  
Mechanical Test ◽  
Sheet Material ◽  
Light Sheet ◽  
Variation Method ◽  
Lap Joint ◽  
Single Lap Joint ◽  
Static Mechanical

Adopting self-piercing riveting (SPR) joining, a new light sheet material joining method, to examine the joining of copper-titanium alloy (H62-TA1) sheet and titanium-aluminum alloy (TA1-Al5052) sheet. Also, using quasi-static mechanical test to figure out mechanical properties of H62-TA1 SPR single-lap joint and TA1-Al5052 SPR single-lap joint. In this study, using Dixon guidelines to eliminate abnormal value and adopting coefficient of variation method to validate reliability of test datum. The results show that failure mode of H62-TA1 joints is that the rivets are pulled out, failure mode of TA1-Al5052 joints is that the bottom sheet fracture. And tensile displacement and energy absorption of H62-TA1 joints are higher than that of TA1-Al5052 joints.

Experimental Study on Dynamic Mechanical Properties of Amphibolites, Sericite-quartz Schist and Sandstone under Impact Loadings

2012 ◽  
Vol 13 (2) ◽  
pp. 209-217
Author(s):  
Jun-Zhong Liu ◽  
Jin-Yu Xu ◽  
Xiao-Cong Lv ◽  
De-Hui Zhao ◽  
Bing-Lin Leng
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Failure Mode ◽  
Failure Modes ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Mechanical Properties ◽  
Tensile Failure ◽  
Strength Increase ◽  
Dynamic Mechanical ◽  
Rock Samples

Abstract In order to investigate rock dynamic mechanical properties of amphibolites, sericite-quartz schist and sandstone under the different strain rates varying from 30 s -1 to 150 s -1 , the specimens were subjected to axial impact at different projectile speeds by using the split Hopkinson pressure bar (SHPB) of 100 mm in diameter. The optimal experimental size of rock samples is verified by analyzing the stress equilibrium of cylindrical rock samples in different thicknesses. It has studied the mechanic properties of these three rocks which under impact loadings; and analysed the dynamic compressive strength, failure modes, energy dissipation variation with the strain-rate and the strain-rate hardening effect from the perspective of material microstructure. Experimental results show that the dynamic Young's modulus of rock samples increase with strain-rate slightly. The dynamic failure modes of different rock samples are always different. When at a lower strain-rate, the damage of sandstone takes a peeling off the external radial tensile failure mode, but that of amphibolites takes axial splitting mode; when at a higher strain-rate, sandstone takes granular crushing failure mode, and that of amphibolites and of sericite-quartz schist take massive crushing mode. Significant strain-rate effect can be represented by a linear relation between the specific energy absorption and the strain-rate , or between the dynamic strength increase factor η and .

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