scholarly journals Reinforced Concrete Plates under Impact Load—Damage Quantification

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4554
Author(s):  
Marcus Hering ◽  
Franz Bracklow ◽  
Silke Scheerer ◽  
Manfred Curbach
Keyword(s):  
Reinforced Concrete ◽  
Impact Load ◽  
Experimental Conditions ◽  
Steel Reinforced Concrete ◽  
Before And After ◽  
Concrete Plates ◽  
The One ◽  
Objective Description ◽  
The Impact ◽  
Impact Experiments

A large number of impact experiments have been carried out at the Technische Universität Dresden in recent years in several research projects. The focus was on reinforced concrete plates on the one hand and on subsequently strengthened reinforced concrete plates on the other hand. Based on these investigations, two fundamental tasks arose: (1) finding an objective description of the damage of components made of steel reinforced concrete that had previously been subjected to an impact load and (2) quantification of the effect of a subsequently applied strengthening layer. In this paper we will focus on both. At first, the experimental conditions and program as well as the used drop tower facility at the Otto Mohr Laboratory of the Technische Universität Dresden are briefly explained. In the summary presentation of the main test results, the focus is on the observed component damage. Based on the observations, an approach for a damage description is presented. To define global damage, the stiffness of the investigated structural components before and after the impact event is used. At the end of the paper, the potential of the method, but also gaps in knowledge and research needs are discussed.

The Impact Load on a Reinforced Concrete Beam

2021 ◽  
pp. 199-245
Author(s):  
Farzad Hejazi ◽  
Hojjat Mohammadi Esfahani
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Impact Load ◽  
Reinforced Concrete Beam ◽  
The Impact

scholarly journals Structural Response to Blast Loading: The Effects of Corrosion on Reinforced Concrete Structures

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hakan Yalciner
Keyword(s):  
Reinforced Concrete ◽  
Concrete Strength ◽  
Plastic Hinge ◽  
Structural Response ◽  
Blast Loading ◽  
Structural Safety ◽  
Terrorist Attacks ◽  
Important Place ◽  
The One ◽  
The Impact

Structural blast design has become a necessary part of the design with increasing terrorist attacks. Terrorist attacks are not the one to make the structures important against blast loading where other explosions such as high gas explosions also take an important place in structural safety. The main objective of this study was to verify the structural performance levels under the impact of different blast loading scenarios. The blast loads were represented by using triangular pulse for single degree of freedom system. The effect of blast load on both corroded and uncorroded reinforced concrete buildings was examined for different explosion distances. Modified plastic hinge properties were used to ensure the effects of corrosion. The results indicated that explosion distance and concrete strength were key parameters to define the performance of the structures against blast loading.

scholarly journals Performance based design of reinforced concrete beams under impact

2010 ◽  
Vol 10 (6) ◽  
pp. 1069-1078 ◽  
Author(s):  
S. Tachibana ◽  
H. Masuya ◽  
S. Nakamura
Keyword(s):  
Reinforced Concrete ◽  
Collision Energy ◽  
Concrete Beams ◽  
Impact Load ◽  
Experimental Results ◽  
Reinforced Concrete Beams ◽  
Performance Based Design ◽  
Impact Action ◽  
The Impact ◽  
A Performance

Abstract. The purpose of this research is to collect fundamental data and to establish a performance-based design method for reinforced concrete beams under perpendicular impact load. Series of low speed impact experiments using reinforced concrete beams were performed varying span length, cross section and main reinforcement. The experimental results are evaluated focusing on the impact load characteristics and the impact behaviours of reinforced concrete beams. Various characteristic values and their relationships are investigated such as the collision energy, the impact force duration, the energy absorbed by the beams and the beam response values. Also the bending performance of the reinforced concrete beams against perpendicular impact is evaluated. An equation is proposed to estimate the maximum displacement of the beam based on the collision energy and the static ultimate bending strength. The validity of the proposed equation is confirmed by comparison with experimental results obtained by other researchers as well as numerical results obtained by FEM simulations. The proposed equation allows for a performance based design of the structure accounting for the actual deformation due to the expected impact action.

Impact-Resistant Performance Analysis of Composite Laminates for Reinforced Concrete Beam Fixed and Hinged at Different Ends

2013 ◽  
Vol 482 ◽  
pp. 30-33
Author(s):  
Run Lin Yang ◽  
Li Zhao ◽  
Juan Hua Zhou
Keyword(s):  
Reinforced Concrete ◽  
Composite Laminates ◽  
Concrete Beam ◽  
Impact Load ◽  
Reinforced Concrete Beam ◽  
Protective Measure ◽  
Protective Effects ◽  
Structural Members ◽  
Protective Measures ◽  
The Impact

Structural members are vulnerable to be damaged under the impact loads. According to traditional design methods, the impact load is seldomly considered. However, recently this situation is changed gradually. In view of this, impact-resistant performance of a new composite protective device was analyzed. A reinforced concrete beam with composite laminates, which was fixed at one end and hinged at the other end, was studied. Totally, the four cases including the unprotected, the rigid, the flexible and the composite protective measures were considered. The protective effects of the different measures can be compared by observing the strain, the displacement, the acceleration and the impact force of the target beam. Simulation results show that the composite protective measure can improve the impact-resistant effect of the target beam significantly and its dynamic response is suppressed effectively.

Three-dimensional effects in low-strain integrity testing of piles: analytical solution

2016 ◽  
Vol 53 (2) ◽  
pp. 225-235 ◽  
Author(s):  
Changjie Zheng ◽  
George P. Kouretzis ◽  
Xuanming Ding ◽  
Hanlong Liu ◽  
Harry G. Poulos
Keyword(s):  
Impact Load ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Integrity Testing ◽  
Integrity Tests ◽  
The One ◽  
Propagation Of Waves ◽  
The Impact ◽  
Pile Integrity ◽  
Elastic Soil

The interpretation of low-strain integrity tests of piles is commonly based on methods developed around the one-dimensional wave propagation theory. In reality, waves resulting from the impact of a hammer on a pile head propagate in three dimensions, and the validity of the plane-front assumption is rather questionable for cases where the size of the hammer is small relative to that of the pile. This paper presents an analytical model of the dynamic response of a pile to an impact load on its head, considering propagation of waves in both vertical and radial directions. The proposed formulation applies to a pile of finite length embedded in multilayered elastic soil, and allows for considering both shape and material pile defects, by reducing locally the radius of the pile cross section or the Young’s modulus of its material. Arithmetic examples are used to depict the effect of high-frequency interferences on the interpretation of pile integrity tests, which can only be accounted for in the three-dimensional formulation of the problem, and lead to practical suggestions for the interpretation of such tests.

A Study for Evaluating Local Damage to Reinforced Concrete Panels Subjected to Oblique Impact: Part 2 — Simulation Analysis of the Experimental Results of Local Damage Caused by Impact of Deformable Projectiles

2017 ◽  
Author(s):  
Akemi Nishida ◽  
Yoshimi Ohta ◽  
Haruji Tsubota ◽  
Yinsheng Li
Keyword(s):  
Reinforced Concrete ◽  
Simulation Analysis ◽  
Impact Load ◽  
Oblique Impact ◽  
Local Damage ◽  
Impact Tests ◽  
Rigid Projectile ◽  
Oblique Impacts ◽  
Simulation Results ◽  
The Impact

Many empirical formulae have been proposed for evaluating the local damage to reinforced concrete structures caused by rigid projectile impact. Most of these formulae are based on impact tests perpendicular to the target structures. To date, few impact tests oblique to the target structures have been conducted. In this study, we aim to obtain a new formula for evaluating the local damage caused by oblique impacts based on previous experimental and simulation results. We analyze and simulate the local damage owing to impact by deformable projectiles. The experimental and simulation results were in good agreement and confirmed the validity of the proposed analytical method. Furthermore, the internal energy of the deformable projectile absorbed upon impact was approximately 60% of the total energy. In comparison to a rigid projectile, it is possible to reduce the impact load and consequently the damage to the target.

scholarly journals Characterization of stony soils' hydraulic conductivity using laboratory and numerical experiments

SOIL ◽  
2016 ◽  
Vol 2 (3) ◽  
pp. 421-431 ◽  
Author(s):  
Eléonore Beckers ◽  
Mathieu Pichault ◽  
Wanwisa Pansak ◽  
Aurore Degré ◽  
Sarah Garré
Keyword(s):  
Hydraulic Conductivity ◽  
Water Flow ◽  
Predictive Models ◽  
Laboratory Experiments ◽  
Saturated Hydraulic Conductivity ◽  
Experimental Conditions ◽  
Rock Fragments ◽  
Unsaturated Hydraulic Conductivity ◽  
The One ◽  
The Impact

Abstract. Determining soil hydraulic properties is of major concern in various fields of study. Although stony soils are widespread across the globe, most studies deal with gravel-free soils, so that the literature describing the impact of stones on the hydraulic conductivity of a soil is still rather scarce. Most frequently, models characterizing the saturated hydraulic conductivity of stony soils assume that the only effect of rock fragments is to reduce the volume available for water flow, and therefore they predict a decrease in hydraulic conductivity with an increasing stoniness. The objective of this study is to assess the effect of rock fragments on the saturated and unsaturated hydraulic conductivity. This was done by means of laboratory experiments and numerical simulations involving different amounts and types of coarse fragments. We compared our results with values predicted by the aforementioned predictive models. Our study suggests that it might be ill-founded to consider that stones only reduce the volume available for water flow. We pointed out several factors of the saturated hydraulic conductivity of stony soils that are not considered by these models. On the one hand, the shape and the size of inclusions may substantially affect the hydraulic conductivity. On the other hand, laboratory experiments show that an increasing stone content can counteract and even overcome the effect of a reduced volume in some cases: we observed an increase in saturated hydraulic conductivity with volume of inclusions. These differences are mainly important near to saturation. However, comparison of results from predictive models and our experiments in unsaturated conditions shows that models and data agree on a decrease in hydraulic conductivity with stone content, even though the experimental conditions did not allow testing for stone contents higher than 20 %.

scholarly journals PERBANDINGAN FAKTOR-FAKTOR YANG MEMPENGARUHI TINGKAT PENGANGGURAN TERBUKA DI INDONESIA SEBELUM DAN SAAT PANDEMI COVID-19

2021 ◽  
Vol 3 (2) ◽  
pp. 25
Author(s):  
Adinda Putri ◽  
Alya Azzahra ◽  
Denita Dwi Andiany ◽  
Dicki Abdurohman ◽  
Prido Putra Sinaga ◽  
...  
Keyword(s):  
Growth Rate ◽  
Unemployment Rate ◽  
Classification Analysis ◽  
Multiple Classification Analysis ◽  
Multiple Classification ◽  
Before And After ◽  
Drastic Increase ◽  
The One ◽  
The Impact

Since Covid-19 arrived in Indonesia, all policies have been carried out to stop the spread of this virus, one of which is the PSBB. The impact of the PSBB is felt by the drastic increase in the number of unemployed in Indonesia. Using Multiple Classification Analysis (MCA), this research was conducted in order to see the condition of the Open Unemployment Rate (TPT) in each province in Indonesia between before and during the pandemic, and to find out the factors that influenced it. The results show that both before and after the pandemic, provinces with an HDI below the national figure led to higher TPT. The growth rate of GDRP and UMP has a different effect between before and during the pandemic. Other results also show that before the pandemic, UMP had the greatest influence on TPT. But after the pandemic, the one that had the biggest impact was HDI.

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.

scholarly journals Impact experiments with reinforced concrete plates of different thicknesses

2019 ◽  
Vol 21 (2) ◽  
pp. 587-598 ◽  
Author(s):  
Marcus Hering ◽  
Franz Bracklow ◽  
Tino Kühn ◽  
Manfred Curbach
Keyword(s):  
Reinforced Concrete ◽  
Concrete Plates ◽  
Impact Experiments
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