The simulations of tests at different charge distances were

The simulations of tests at different charge distances were carried out. Table 3 lists the calculated results. The results showed that oxycodone hydrochloride the distribution of fragments is random, which leads to the random reaction results of acceptors. With the increase in the charge distance, the acceptor detonated easily. The calculated critical distance range is about from 140 mm to 300 mm, which is in agreement with the results of tests mainly. Fig. 10 showed the calculated deformation of the acceptors at different time at 200 mm charge distance. As the donor exploded, the fragments with different sizes were formed and flied around; some of them impacted the acceptors. At 115 μs, the fragments began to impact Acceptor 1#. Under the impact of fragments, the internal pressure of charges increased, and the detonation waves grew up along the charge. At 165 μs, Acceptor 1# detonated completely, while Acceptor 2# was initiated just now, but Acceptor 3# and Acceptor 4# did not detonate at last.
Conclusions
Introduction The pitch bearing of a wind-power generator is basically a single row four-point contact bearing or a double row four-point contact bearing with either an internal gear or an external gear. It is installed in a high place ranging from 40 m to 60 m. The installation and replacement of the pitch bearing are very inconvenient, and its cost is higher [1]. Therefore, the pitch bearings are requested to have a service life of twenty years and high reliability [2]. Because the impact load acting on the pitch bearing is very large, the zero or negative clearance is considered to reduce fretting wear. Negative clearance not only affects the startup torque, rotation precision and stiffness of bearing, but also affects the load capacity and life of bearing. It is of great significance to research the effect of negative clearance on contact load distribution and load-carrying capacity. Because the running speed of a pitch bearing is usually small, the static load-carrying capacity, which can be described by the static load-carrying curves, is mainly considered in the pitch bearing design. The single row four-point contact ball bearing was discussed in Refs. [3–14], and the research on the large-sized double or three row four-point contact ball bearings was discussed in Refs. [15–18]. A calculation procedure for determining the load distribution in the rolling elements of a four contact-point slewing bearing with one row of balls was discussed in Ref. [3]. The ball motion and sliding friction in the double arched ball bearing were analyzed in Ref. [4]. The calculation method of the static load-carrying curve for turntable bearings was discussed in Refs. [8,9]. A computational model for determining the static load capacity and fatigue lifetime of a large slewing bearing was described in Ref. [14]. Static analysis of a double row four-point contact ball bearing was described in Refs. [16,17]. All papers above described the static model without taking into account the clearance of bearing, especially the negative clearance. In this paper, taking a double row four-point contact ball bearing for example, the geometry model, static force model and the method to establish the static load-carrying curve considering the effect of negative clearance were presented.
Static model
Determination of static load-carrying capacity curve
Results and discussion
Conclusions
Acknowledgments This research was supported by NSFC (51105131), Excellent Youth Foundation of Henan Scientific Committee (124100510002) and Creative Talent Foundation in University of Henan Province (2011HASTIT016)
Introduction Drop tests are credible to research airbag landing attenuation system but too expensive. The safety and time are the other two key problems. Thus Trans configuration is practically impossible to optimize the parameters of airbag landing attenuation system for heavy airdrop only by experimental methods. Development of simulation technology makes the problems overcome. Several simulation models of airbag were established [1–3]. It\'s feasible to optimize the parameters of airbag landing attenuation system for heavy airdrop using simulation technology.