Sharif Digital Repository

The assessment of existing platforms under past environmental (wave, wind, current and etc.) loads and probable future loads (earthquake) is a relatively new process and has not yet been standardized as the design has. This lack of standardization creates some difficulty in establishing performance requirements which must be developed depending upon the risks (i.e., hazards, exposures and consequences) associated with the future operation of the platform. The present criteria of the offshore structure standards for seismic assessment can be improved using Building prestandards. Recently some documents such as FEMA-356 and ATC-40 are developed for seismic assessment of buildings. However... 

The role of initiators with different reactivities on the process cycle of nonisothermal resin transfer molding (RTM) was examined using the numerical simulation. A new process model was developed based on flow, heat and mass transfer equations combined with an appropriate mechanistic kinetics model which elucidates the functions of the initiators in the system. The process cycle of RTM with both single initiator and dual-initiator (combination of two initiators) was analyzed. The numerical simulations revealed that the single initiator with high reactivity reduces the cycle time, but there is a risk of incomplete mold filling and nonuniform temperature distribution. For dual-initiator...