Advanced Materials Research Vols. 1030-1032

Abstract: Adding polymer emulsion to concrete can increase the bonding strength at the interface of steel fiber and matrix and the property of matrix is improved. Tensile strength, bending strength, deformation and toughness of the concrete are also increased. Anti-penetration performance of steel fiber reinforced concrete (SFRC), polymer-modified concrete (PMC) and steel fiber reinforced polymer-modified concrete (SFRPMC) are studied in this paper. Experiment was conducted by launching steel projectiles into concrete targets, and damage distributions of concrete after penetration are obtained. The results showed the anti-penetration performance of steel fiber concrete by adding polymer can be increased obviously.

Abstract: Polymer-modified concrete is widely used for the rehabilitation of old damaged structures mainly due to its good adhesive performance. The interfacial bond strength between polymer-modified concrete and plain concrete should be measured carefully in order to keep both sides work together. To overcome problems existed in the test of bond strength between two types of concretes, a split apparatus was designed. Experiments on bond strength between plain concrete and polymer-modified concrete with different polymer contents and different interfacial treatments were conducted utilizing the newly devised apparatus, and a series of complete and correct results were obtained. The experimental results indicate that when the surface is treated with 10% polymer solution, the bond strength between plain concrete and polymer-modified concrete with polymer-cement ratio at 15% is better than those in other cases.

Abstract: Joint load transfer ability is the key part of the analysis of the rigid pavement structure. This paper is focused on the load transfer efficiency at joints of monolithic track-bed under new city tramcar loading. Based on the general finite element analysis software ABAQUS, the relationship between the modulus of virtual materials in virtual material layer method and joint load transfer ability is analyzed. Meanwhile, bending stress and deflection for monolithic track-bed structure on edge loading case are calculated under different thickness of the pavement structure.

Abstract: With China's rapid economic development, traffic and heavy-duty vehicles increased significantly. Asphalt pavement failure caused by heavy traffic is increasingly prominent.Pavement's service life was greatly reduced. On the basis of extensive research and theoretical calculation the article analyzes the impact of heavy traffic on the asphalt pavement service life from three aspects of rutting,ultimate failure and fatigue failure, provides a theoretical basis for heavy traffic asphalt pavement structure design.

Abstract: With the rapid development of our economy, also promotes the development of our country road. Though the road construction starts relatively late in our country, but its development is very quick. However, due to the technology is not very mature, and the road load is bigger, and the influence of climate and so on, makes appeared different degree of damage of asphalt pavement. So how to improve the quality of the road is also became a problem to be solved in engineering. This article mainly from the problems existing in the construction process, the influence of natural factors and human factors, analyses the reason of pavement damage, and how to detect damage of asphalt pavement.

Abstract: In order to seek reasonable evaluation methods of anti-skid function on asphalt pavement, we summarized many domestic skid resistance and durability test equipments for asphalt pavement and it’s test methods. Analyzed its advantages and disadvantages and discussed the current anti-sliding and anti-wear test method listed in specifications,which have great significance on the future development of anti-sliding test equipment and the improvement of the anti-sliding test method.

Abstract: A simplified mathematic model of hydro-pneumatic suspension was set up and the damping characteristic curve of hydro-pneumatic suspension was obtained accordingly. A analysis of the effect of diameter of hydraulic jar, velocity of piston, diameter of damping hole and check valve diameter on damping characteristic of hydro-pneumatic suspension was made. It showed that the major influence factors includes moving speed of piston, diameter of hydraulic jar and diameter of damping hole.

Abstract: Residual life prediction is a critical and difficult problem in condition-based maintenance decision-making. Aiming to deal with the problems that practical data is limited and the estimation of initial parameters is not accurate in maintenance practice, a residual life prediction method for gearbox based on stochastic filtering (SF) is proposed. In this method, recursive expectation maximization (REM) algorithm is introduced to update the parameters, and a maximum likelihood estimation method is designed to update the unknown parameters. Finally, the validity and practicability of the model are validated by an example.

Abstract: All the drive motor of AGV are DC servo motor in the domestic stage , but it has some shortcomings such as more power consumption ,noise, magnet coils easy to burn, life is short and so on in the actual production. Through two series of comparative tests on the DC motor and AC motor driven AGV get two drive mode start time, start acceleration, top speed and other values.Through numerical processing and analysis know that AC motor as a AGV drive motor is better than Dc servo motor..

Abstract: Involute helical gears, with advantages of large carrying capacity, smooth transmission and long life, etc., are widely used in automotive, mining, helicopters and other high-speed and heavy-load transmission system. Poor working conditions lead to fatigue crack and other faults of gear key parts such as tooth root and tooth face. To identify the root causes of gear faults, strain monitoring methods are often used to monitor the stress changes of gear key parts so as to work out individualized improvement plants. Good test results can be obtained using real-time wireless data collection technology when the gear is in low-speed and light loading condition, and we can get important data such as speed, torque and dynamic strain on tooth root, etc. However, involute helical gears tend to work in high-speed and heavy harsh conditions, especially when the gear speed reaches a large value (eg. 10000r/min above), gear strain measurement device will suffer big centrifugal force and the impact of shear force which may results partial bonded adhesive failure (cracks, erosion, etc.) and even whole peeling of strain gages, thus inaccurate and even error results will be obtained. Transient finite element analysis method is used in this paper to study the relationship between rotation velocity and test accuracy of strain gauge as well as the process of the bonded adhesive failure, which may provide effective guidance for the fault diagnoses of gear meshing.