Robot driver for vehicle durability emission test on chassis dynamometer

A method for a vehicle durability emission test using a robot driver insteadof human drivers on the chassis dynamometer is presented. The system architecture of vehicledurability emission test cell, the road load simulation strategy and the tele-monitoring systembased on Browser/Client structure are described. Furthermore, the construction of the robot driver,vehicle performance self-learning algorithm, multi-mode vehicle control model and vehicle speedtracking strategy based on fuzzy logic arealso discussed. Besides, the capability of controlparameters self-compensation on-line makes it possible to compensate the wear of vehicle componentsand the variety of clutch true bite point during the long term test. Experimental results show thattherobot driver can be applicable to a wide variety of vehicles and the obtained results stay withina tolerance band of ± 2 km/h. Moreover the robot driver is able to control tested vehicles withgood repeatability and consistency; therefore, this methodpresents a solution to eliminate theuncertainty of emission test results by human drivers and to ensure the accuracy and reliability ofemission test results.

Experimental Design on Laminated Veneer Lumber Fiber Reinforced Composite： Processing Parameters and Its Durability

The investigating of the hot press process parameters on the flexural properties of LVL （Laminated Veneer Lumber） reinforced composites derived from rubber wood veneer reinforced with fiber glass woven and epoxy adhesive were performed via the DOE （design of experimental） approach. It was discovered that pressure was the most significantly and negatively effect on the product properties. Enhancing in the mechanical properties was related to decrease the processing pressure. Beside, press time was also significantly and positively effect. Although time was not clearly reflect from the mechanical results, but it was detected from the ANOVA （analysis of variance）results. The mechanical properties were increased with increasing compression time. From the results, the optimal condition to maximize mechanical properties was assumed at low pressure, 15 bars, low temperature, 70℃, and long time, 60 mins. The durability testing including screw nail withdrawal strength, water absorption, and termite resistance of LVL reinforced composite were also studied. The results are shown that the LVL wood has superior properties when compare with solid woods. It was found the withdrawal strength of LVL reinforce composite was higher than the solid woods. As expected that solid woods, except eucalyptus, had low water absorption resistance as it more hygroscopic corresponded to LVL reinforced wood. Also solid woods, except teal（, had low resistance to termite attack. Therefore, LVL reinforced was the best candidate by mean of durability properties compared to solid wood.

Experimental investigation on freeze-thaw durability of polymer concrete

Assessing the durability of concrete is of prime importance to provide an adequate service life and reduce the repairing cost of structures.Freeze-thaw is one such test that indicates the ability of concrete to last a long time without a significant loss in its performance.In this study,the freeze-thaw resistance of polymer concrete containing different polymer contents was explored and compared to various conventional cement concretes.Concretes’fresh and hardened properties were assessed for their workability,air content,and compressive strength.The mass loss,length change,dynamic modulus of elasticity,and residual compressive strength were determined for all types of concretes subjected to freeze-thaw cycles according to ASTM C666-procedure A.Results showed that polymer concrete(PC)specimens prepared with higher dosages of polymer contents possessed better freeze-thaw durability compared to other specimens.This high durability performance of PCs is mainly due to their impermeable microstructures,absence of water in their structure,and the high bond strength between aggregates and a polymer binder.It is also indicated that the performance of high-strength concrete containing air-entraining admixture is comparable with PC having optimum polymer content in terms of residual compressive strength,dynamic modulus of elasticity,mass loss,and length change.

Nanomagnetic CoPt truncated octahedrons:facile synthesis,superior electrocatalytic activity and stability for methanol oxidation

Nanomagnetic CoPt truncated octahedral nanoparticles （TONPs） were successfully synthesised through a facile one-pot strategy. These single crystal CoPt TONPs with an average size of about 8 nm exhibit excellent electrocatalytic performance of both activity and stability for methanol oxidation reaction （MOR）. The mass and specific activities of CoPt TONPs is 8 and 6 times higher than that of standard commercial Pt/C, respectively. After accelerated durability test （ADT）, the loss of electrochemical surface area （ECSA） for CoPt TONPs is only 18.5%, which is significantly less than that of commercial Pt/C （68.2%）, indicating that CoPt TONPs possess much better stability than commercial Pt/C in the prolonged operation. The Curie temperature of CoPt TONPs down to 8 nm is as high as 350 K with weak ferromagntism at room temperature （RT）, which is greatly valuable for recycling in the eletrocatalytic applications.

Leakage and wear characteristics of carbon seals for aero-engines

Experimental investigation has been performed to study the leakage and wear characteristics of carbon seal working at high circumferential speed. To expand the scope of application, two newly designed carbon seals were compared: #1 Carbon Seal(CS1) with the inner diameter of136 mm and including 4 segments, #2 Carbon Seal(CS2) with the inner diameter of 212 mm and including 6 segments. Air leakage tests were firstly conducted in the Medium-speed Seal Test Rig. The pressure ratio changed from 1.04 to 2.02 with the rotating speed varying from 0 to18300 r/min. Of paramount concern was the durability test, including 300 h running time accumulated by three different working conditions, which was separately implemented on each carbon seal.The morphology variation of the friction surface, wear and leakage were recorded. Results indicated that the leakage monotonously increases with the pressure ratio and decreases with the rotating speed. Comparing with CS1, more typical features exist on the friction surface of CS2, which are generated by more severe wear. Continually, leakage characteristics deteriorate. Furthermore, fitted formula has been educed for the life prediction of carbon seal, which could provide some supports for aero-engine design.