Effect of the axial load on the dynamic response of the wrapped CFRP reinforced concrete column under the asymmetrical lateral impact load.

This study investigated the impact of axial load on the dynamic response of reinforced concrete (RC) members to asymmetrical lateral impact loads. A series of asymmetrical-span impact tests were conducted on circular and square RC members with and without Carbon Fiber Reinforced Polymers (CFRP) while varying the axial compression ratios. The impact process was simulated using ABAQUS software, and the time history curves of deflection and impact were measured. The study found that specific impact loads caused bending and shearing failures. The axial compression ratio ranged from 0.05 to 0.13 when the impact curve reached its maximum deflection before the component's impact resistance decreased. Analysis of the impact point and inclined crack location revealed that axial load affects the maximum local concrete. The speed of inclined crack penetration and inclined cracks take longer to form, with weaker resistance to damage to local concrete when the axial compression ratio is between 0.05 and 0.13. When the axial compression ratio is greater than 0.13, inclined cracks form sooner with more brittle and severe damage to the impact point's concrete. The study also identified key parameters affecting the dynamic response of RC members, including impact height, CFRP layer thickness, axial force, and impact location. Thicker CFRP layers in RC can improve impact resistance, especially when the impact location is farther from the center. However, there is a limit to the impact of axial force on this resistance.

Numerical study on existing RC circular section members under unequal impact collision.

Traffic accidents and derailed train-related incidents have occurred more often than ever in recent years, resulting in some economic damage and casualties. Reinforced concrete (RC) constructions often involve derailed train and vehicle accidents. Rarely are such side collisions studied in previous studies. To do this, high-fidelity simulation-based finite-element (FE) models are created in this paper to accurately simulate the collision of circular RC members with a derailed train. The reinforced concrete member structure is common in high-speed railway stations. The impact energy of the impact body is significant, causing structural member failure. It analyses the dynamic behavior of reinforced concrete members under unequal span impact loads. Numerical implementations of impact issues are discussed from the perspective of geometric, contact, and material properties. The reliability and precision of the ABAQUS code to solve impact issues are verified by comparing failure modes, impact, and deflection time history experimental outputs. By analysing the impact response characteristics, used the control variables to study the failure process and mode (including the characteristics of impact and reaction forces, deflection time history curve, impact force-deflection curve, and bearing reaction force-deflection curve). The reinforcement ratio, impact velocity, concrete strength, and slenderness ratio significantly affect shear crack pattern and development. Changes in impact velocity and slenderness ratio also affect member failure modes.

Dynamic Equilibrium of CFRP-RC Square Elements under Unequal Lateral Impact.

Building structure regularly needs reinforcement due to damage, specification requirements, and functional changes; carbon fiber reinforced polymer (CFRP) is widely used in structural reinforcement due to its high strength, lightweight, good corrosion resistance and easy construction. The regular square section reinforced concrete frame elements strengthened by CFRP material are taken as the research object. The dynamic response of CFRP to reinforced concrete elements under unequal lateral impact was discussed. This technical paper demonstrates that the test elements are subject to the bending failure mode, and the impact point and the near impact point support are severely damaged areas; the transversely wrapped elements are more abruptly broken, and the longitudinal wrapping elements and the number of wrapping layers can effectively reduce the level of damage. Analysis of the impact, deflection, and strain time history curves obtained in the test show that the wrapping mode and the number of layers have less influence on the impact force peak; the longitudinally wrapped elements and the plateau segment take longer. Dynamic equilibrium principle equation was proposed based on the experimental results. The horizontal partition plateau segment fluctuates greatly; the number of vertical wrap layers increases the plateau value. The larger the number of layers, the smaller the deflection caused by the impact. The longitudinal wrapping can effectively transmit the force.

A Survey of Aesthetic Standards of the Ear.

BACKGROUND: The aesthetic standards of the ear are very important for evaluation of auricular surgery. Few studies have previously assessed ear aesthetics, especially in China. This study aimed to investigate aesthetic standards of the ear in a Chinese population. MATERIALS AND METHODS: A questionnaire was administered to Chinese individuals, which included assessment of the general impressions of the ear and other facial aesthetic units, the individual aesthetic subunits of the ear, the effects of different ear subunits on ear symmetry and the degree of the subunits to which the participants wanted to change. Answers were recorded on a five-point Likert-style scale. Statistical analysis was performed using SPSS ver. 17.0. RESULTS: A total of 319 responses were received, 50.3% women and 49.7% men. The external ear received the lowest degree of attention either on the front or on the lateral view of the face in both genders. Among the individual aesthetic units, the earlobe received the most attention and the fine structures the lowest. The helix had the greatest effect on the ear symmetry. The structure that participants most wanted to change was the earlobe in males and the helix in females. There were significant differences on the evaluation of the helix and crus of helix among the groups divided according to educational background (P < 0.001). CONCLUSION: The results showed that the structures that people were most concerned about were the helix and earlobe. There were gender differences in the results which were also influenced by education background.

Measurement of auricle development related indexes and its application for auricular reconstruction / 中华整形外科杂志

Objective@#To analyze growth changes in the ear by measuring the width and length of ears in a Chinese population and its application for auricular reconstruction.@*Methods@#A total of 480 participants were enrolled into 1 year, 3 years, 5 years, 7 years, 9 years, 12 years, 14 years and adult groups (half were boys and half were girls in each group). Ear length and width were measured and recorded. Ear index was calculated according to ear length and ear width. The growth of auricle and differences between genders were analyzed.@*Results@#Ear length and width increased with age. Ear length achieved its mature size in both 14-year-old males and females. Ear width reached its mature size in males of 7 years and in females of 5 years. Different trends of ear index were shown between males and females.@*Conclusions@#The data indicated that ear developed with age. There were gender and ethnic difference in the development of ear. Ear reconstruction should not be performed when the age of patient is less than 12 years old, if only the development of ear width is considered, the age of patient for surgery to be performed should not be less than 7 years old.