scholarly journals Experimental Study and Numerical Analysis on Impact Resistance of Civil Air Defense Engineering Shear Wall

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Chenglong Shi ◽  
Jigang Zhang ◽  
Junbo Zhang ◽  
Feng Shao ◽  
Yicong Zhang ◽  
...  
Keyword(s):  
Impact Load ◽  
Impact Resistance ◽  
Great Influence ◽  
Shear Walls ◽  
Horizontal Displacement ◽  
Shear Wall ◽  
Factors Affecting ◽  
Air Defense ◽  
Impact Surface ◽  
The Impact

In order to study the impact resistance of civil air defense engineering shear wall, the impact resistance of civil air defense engineering shear wall was studied by combining finite element numerical simulation with pendulum impact test. The effects of impact height, pendulum mass, and impact times on the impact resistance of civil air defense engineering shear walls were analyzed. It was shown that when the impact height increased from 0.4 m to 2.5 m, the failure mode of civil air defense engineering shear wall tended to be local impact failure, and the horizontal displacement in the middle of the wall span increased. The concrete crushing occurred in the impact area of the back of the civil air defense engineering shear wall. The increase in the impact height is a negative factor for the impact resistance of the civil air defense engineering shear wall. With the increase of pendulum weight, the number of concrete horizontal cracks in the back of the civil air defense engineering shear wall increased, while the number of vertical cracks decreased, but the impact surface was destroyed. Through multiple impact tests on the civil air defense engineering shear wall, the civil air defense engineering shear wall had accumulated damage. The longitudinally loaded steel on the back reached the ultimate strength, and there are large cracks at the bottom and even collapses. The increase of impact times has a great influence on the impact resistance of the civil air defense engineering shear wall. Through the analysis of the factors affecting the impact resistance of civil air defense engineering shear wall, it provides guidance for civil air defense engineering shear wall to resist impact load.

scholarly journals Impact Resistance Analysis and Optimization of Variant Truss Beam Structure Based on Material Properties

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5847
Author(s):  
Xiaohao Li ◽  
Junqi Pan ◽  
Xingchen Zhou
Keyword(s):  
Simulation Analysis ◽  
Impact Load ◽  
Impact Resistance ◽  
Structure Design ◽  
Response Surfaces ◽  
Optimization Strategy ◽  
Buffer Effect ◽  
Characteristic Analysis ◽  
Beam Structure ◽  
The Impact

In order to meet the increasing application requirements with regards to structural impact resistance in industries such as mining, construction, aerospace engineering, and disaster relief and mitigation, this paper designs a variant truss beam structure with a large shrinkage ratio and high impact resistance. Based on the principle of the curved trajectory of scissor mechanisms, this paper conducts a finite element simulation analysis of the impact load on the truss beam structure, a theoretical analysis of the impact response and a relevant prototype bench-top experiment, completing a full study on the impact resistance mechanism of the designed variant truss beam structure under the impact load. In the paper, the buffer effect of the external load impact on the variant truss beam structure is analyzed from the perspective of the energy change of elastic–plastic deformation. This paper proposes an optimization strategy for the variant truss beam structure with the energy absorption rate as the optimization index through extensive analysis of the parameter response surfaces. The strategy integrates analyses on the response characteristic analysis of various configuration materials to obtain an optimal combination of component parameters that ensures that the strength of the truss beam structure meets set requirements. The strategy provides a feasible method with which to verify the effectiveness and impact resistance of a variant truss structure design.

scholarly journals Impact Response of Hammerhead Pier Fibrous Concrete Beams Designed with Topology Optimization

2020 ◽  
Author(s):  
Meivazhisalai Parasuraman Salaimanimagudam ◽  
Covaty Ravi Suribabu ◽  
Gunasekaran Murali ◽  
Sallal R. Abid
Keyword(s):  
Topology Optimization ◽  
Concrete Beams ◽  
Impact Load ◽  
Impact Resistance ◽  
Adaptive Mesh ◽  
Impact Response ◽  
Adaptive Meshing ◽  
Repeated Impact ◽  
Ductility Ratio ◽  
The Impact

Reducing the weight of concrete beams is a primary (beyond strength and durability) concern of engineers. Therefore, this research was directed to investigate the impact response of hammerhead pier concrete beams designed with density-based method topology optimization. The finite element topology optimization was conducted using Autodesk fusion 360 considering three different mesh sizes of 7 mm, 10 mm, and adaptive meshing. Three optimized hammerhead beam configurations; HB1, HB2, and HB3, respectively, with volume reductions greater than 50 %. In the experimental part of this research, nine beams were cast with identical size and configuration to the optimized beams. Three beams, identical to the optimized beams, were tested under static bending for verification purposes. In comparison, six more beams, as in the preceding three beams but without and with hooked end steel fibers, were tested under repeated impact load. The test results revealed that the highest flexural capacity and impact resistance at crack initiation and failure were recorded for the adaptive mesh beams (HB3 and HB3SF). The failure impact energy and ductility ratio of the beam HB3SF was higher than the beams HB1SF and HB2SF by more than 270 %. The results showed that the inclusion of steel fiber duplicated the optimized beam’s impact strength and ductility several times. The failure impact resistance of fibrous beams was higher than their corresponding plain beams by approximately 2300 to4460 %, while their impact ductility ratios were higher by 6.0 to 18.1 times.

Dynamic Analysis of Liquid Sloshing for Shipboard Pressure Vessel

2020 ◽  
Author(s):  
Qi Li ◽  
Hui Tang ◽  
Fujun Zhang ◽  
Zhijian Wang ◽  
Qianyu Shi
Keyword(s):  
Dynamic Analysis ◽  
Pressure Vessel ◽  
Impact Load ◽  
Great Influence ◽  
Liquid Sloshing ◽  
Pressure Curve ◽  
Operation Condition ◽  
Device Structure ◽  
Safety Operation ◽  
The Impact

Abstract With the development of pressure vessel industry in China, more and more pressure vessel is widely used in the aerospace, automobile, marine project and other fields. The liquid sloshing in the device could bring adverse effect on the safety operation of the pressure vessel under the extrinsic excitation, such as the impact load results in the failure of device structure. Thus, dynamic analysis of liquid sloshing for the shipboard pressure vessel is significant. According to the little research on the design criteria and the method of the shipboard pressure vessel, this paper focuses on the research of the transient sloshing of the internal liquid in the shipboard pressure vessel. In this paper, during analyzing the liquid sloshing dynamic of the shipboard pressure vessel, an obvious cycle is got. Considering the operation condition of lateral inclination, longitudinal inclination and heave in the complex marine environment, the liquid sloshing character is obtained and compared through the liquid surface height curve and the wall sloshing pressure curve, which has great influence on the piping layout of the pressure vessel. Moreover, it is beneficial to restrain sloshing through installing baffle inside the pressure vessel. This may provide a project reference to liquid sloshing design of the shipboard pressure vessel.

scholarly journals A review of fibrous materials for soft body armour applications

RSC Advances ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 1066-1086 ◽  
Author(s):  
Unsanhame Mawkhlieng ◽  
Abhijit Majumdar ◽  
Animesh Laha
Keyword(s):  
Critical Review ◽  
Impact Resistance ◽  
Fibrous Materials ◽  
Soft Body ◽  
Factors Affecting ◽  
Body Armour ◽  
The Impact

A critical review on the factors affecting the impact resistance and various approaches adopted to enhance the performance of soft body armour materials is presented here.

scholarly journals Axial Impact Load of a Concrete-Filled Steel Tubular Member with Axial Compression Considering the Creep Effect

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3134 ◽  
Author(s):  
Tao Lan ◽  
Guangchong Qin ◽  
Jinzhao Zhuang ◽  
Youdi Wang ◽  
Qian Zheng ◽  
...  
Keyword(s):  
Impact Load ◽  
Slenderness Ratio ◽  
Concrete Strength ◽  
Pressure Ratio ◽  
Impact Resistance ◽  
Axial Pressure ◽  
Axial Impact ◽  
Creep Effect ◽  
The Impact ◽  
Peak Value

The dynamic loads acting on concrete-filled steel tubular members under axial impacts by rigid bodies were studied herein by FEM. The whole impact process was simulated and the time history of the impact load was obtained. The effects of eight factors on the axial impact load were studied; these factors were the impact speed, mass ratio, axial pressure ratio, steel ratio, slenderness ratio, concrete strength, impact position, and boundary conditions. Besides this, the effects of concrete creep on the impact load were also considered by changing the material parameters of the concrete. The results show that axial impact load changes with time as a triangle. The peak value of impact load increases and the impact resistance improves with the growth of the axial pressure ratio, steel ratio, slenderness ratio, and concrete strength after creep occurs. As the eccentricity of the axial impact acting on a concrete-filled steel tubular member increases, the peak value of the impact load decreases. The enhancement of constraints at both ends of the member can improve the impact resistance. The creep reduction coefficients for the peak axial impact load of a concrete-filled steel tubular member under axial compression and considering the creep effect over 6 months and 30 years are 0.60 and 0.55, respectively. A calculation formula for the peak value of impact load was suggested based on the existing formula, and its accuracy was proved by finite element calculation in this study.

scholarly journals Experimental Investigation on Relations Between Impact Resistance and Tensile Properties of Cement-Based Materials Reinforced by Polyvinyl Alcohol Fibers

2019 ◽  
Vol 9 (20) ◽  
pp. 4434
Author(s):  
Ju Zhang ◽  
Pucun Bai ◽  
Changwang Yan ◽  
Shuguang Liu ◽  
Xiaoxiao Wang
Keyword(s):  
Polyvinyl Alcohol ◽  
Tensile Properties ◽  
Impact Load ◽  
Impact Resistance ◽  
Crater Diameter ◽  
Cement Based Materials ◽  
Weight Test ◽  
Ultimate Failure ◽  
Drop Weight Test ◽  
The Impact

Cement-based material is brittle and is easily damaged by an impact load with a few blows. The purpose of this paper is to study the relations between the impact resistance and tensile properties of cement-based materials reinforced by polyvinyl alcohol fiber (PVA-FRCM). A drop-weight test and uniaxial tension test were performed. The relations were studied based on the experimental results, including the relation between the blow number and the tensile stress at the first visible cracking (σc) and the relation between the blow number and the tensile strain at the ultimate failure (εf). Results showed that the blow number for the first visible crack for disc impact specimens increases obviously with the increase of σc of slab specimens. The crater diameter and blow number for ultimate failure of the disc specimens increase with the increase of εf of slab specimens. For the PVA-FRCM specimens with larger σc and εf, much more blows are needed to cause both the first visible crack and ultimate failure. Polyvinyl alcohol fibers can reinforce impact resistance and tensile properties of cement-based materials.

scholarly journals Experiment and Simulation Study on the Dynamic Response of RC Slab under Impact Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yue Wang ◽  
Jun Liu ◽  
Zhimin Xiao ◽  
Futian Zhao ◽  
Yi Cheng
Keyword(s):  
Dynamic Response ◽  
Impact Loading ◽  
Impact Resistance ◽  
Great Influence ◽  
Time History ◽  
Reinforcement Ratio ◽  
Slab Thickness ◽  
Drop Hammer ◽  
Rc Slab ◽  
The Impact

Reinforced concrete (RC) slab is an important component in civil construction and protection engineering, and its dynamic response under impact loading is a complex mechanical problem, especially for two or multiple continuous impact loads. In this paper, a series of drop hammer impact tests were carried out to investigate the dynamic response of RC slabs with two successive impacts. The time history of impact force and the failure characteristic of the slab surface were recorded. Moreover, four influence factors, including slab thickness, reinforcement ratio, impact location, and drop hammer height have been discussed. Besides, a 3D numerical model based on the finite element method (FEM) was established to expand the research of constrained force, deflection, and vertical stress of an RC slab. The results show that increasing the slab thickness and reinforcement ratio can improve the impact resistance of an RC slab. The impact point location and drop hammer height have a great influence on the dynamic response of the RC slab. In addition, the RC slab will have more obvious damage under the second impact, but the dynamic response becomes weaker. It may be because of the local damage in the concrete caused by the first impact that would weaken the propagation of vibration.

scholarly journals DYNAMIC IMPACT WEAR AND IMPACT RESISTANCE OF W-B-C COATINGS

2020 ◽  
Vol 27 ◽  
pp. 37-41
Author(s):  
Josef Daniel ◽  
Jan Grossman ◽  
Vilma Buršíková ◽  
Lukáš Zábranský ◽  
Pavel Souček ◽  
...  
Keyword(s):  
Impact Test ◽  
Impact Load ◽  
Protective Coatings ◽  
Impact Resistance ◽  
Impact Testing ◽  
The Novel ◽  
Test Results ◽  
Dynamic Impact ◽  
Impact Deformation ◽  
The Impact

Coated components used in industry are often exposed to repetitive dynamic impact load. The dynamic impact test is a suitable method for the study of thin protective coatings under such conditions. Aim of this paper is to describe the method of dynamic impact testing and the novel concepts of evaluation of the impact test results, such as the impact resistance and the impact deformation rate. All of the presented results were obtained by testing two W-B-C coatings with different C/W ratio. Different impact test results are discussed with respect to the coatings microstructure, the chemical and phase composition, and the mechanical properties. It is shown that coating adhesion to the HSS substrate played a crucial role in the coatings’ impact lifetime.

Inelastic analysis of a reinforced concrete shear wall building according to the National Building Code of Canada 2005

2006 ◽  
Vol 33 (7) ◽  
pp. 854-871 ◽  
Author(s):  
M Panneton ◽  
P Léger ◽  
R Tremblay
Keyword(s):  
Reinforced Concrete ◽  
Three Dimensional ◽  
Time History ◽  
Shear Walls ◽  
Shear Wall ◽  
Fundamental Period ◽  
Building Code ◽  
Base Shear ◽  
Inelastic Analysis ◽  
The Impact

An eight-storey reinforced concrete shear wall building located in Montréal and designed according to the 1995 National Building Code of Canada (NBCC) and the Canadian Standards Association standard CSA-A23.3-94 is studied to evaluate the impact of new requirements for inclusion in new editions of the NBCC and CSA-A23.3. Static and modal analyses were conducted according to the 2005 NBCC (draft 2003) and CSA-A23.3-04 (draft 4) procedures, and three-dimensional dynamic inelastic time history analysis was performed using three earthquake records. The building is braced by four flat shear walls and three cores. Various estimates of the fundamental period of vibration based on empirical expressions presented in the literature or structural models with different stiffness assumptions were examined. The analysis also permitted the study of the displacement and force demand on the lateral load resisting system. It was found that the base shear from the 2005 NBCC is 29% higher than the 1995 NBCC value when code empirical formulae are used for the fundamental period of vibration.Key words: building, shear wall, inelastic seismic response, NBCC, CSA-A23.3 design of concrete structures.

scholarly journals Effect of Strengthening Methods on Two-Way Slab under Low-Velocity Impact Loading

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5603
Author(s):  
Sun-Jae Yoo ◽  
Tian-Feng Yuan ◽  
Se-Hee Hong ◽  
Young-Soo Yoon
Keyword(s):  
Reinforced Concrete ◽  
High Performance Concrete ◽  
Impact Load ◽  
Reaction Force ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Low Velocity Impact ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slabs ◽  
The Impact

In this study, the performance of reinforced concrete slabs strengthened using four methods was investigated under impact loads transferred from the top side to bottom side. The top and bottom sides of test slabs were strengthened by no-slump high-strength, high-ductility concrete (NSHSDC), fiber-reinforced-polymer (FRP) sheet, and sprayed FRP, respectively. The test results indicated that the test specimens strengthened with FRP series showed a 4% increase in reaction force and a decrease in deflection by more than 20% compared to the non-strengthened specimens. However, the specimen enhanced by the NSHSDC jacket at both the top and bottom sides exhibited the highest reaction force and energy dissipation as well as the above measurements because it contains two types of fibers in the NSHSDC. In addition, the weight loss rate was improved by approximately 0.12% for the NSHSDC specimen, which was the lowest among the specimens when measuring the weight before and after the impact load. Therefore, a linear relationship between the top and bottom strengthening of the NSHSDC and the impact resistance was confirmed, concluding that the NSHSDC is effective for impact resistance when the top and bottom sides are strengthened. The results of the analysis of the existing research show that the NSHSDC is considered to have high impact resistance, even though it has lower resistance than the steel fiber reinforced concrete and ultra-high-performance-concrete, it can be expected to further studies on strengthening of NSHSDC.

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