Within the engineering industry, evaluation of a post-installed glass fiber reinforced polymer and honeycomb system over steel is evaluated on how it can help reduce critical kinetic energy (CKE) onto steel storage tanks caused from wind-borne debris. Determining an accurate formula for CKE for steel has also been an on-going process for years. This research helps determine a valid equation. Existing equations of CKE have been evaluated and compared to data.
Three laboratory tests were performed, and one finite element modeling (FEM) was evaluated. Laboratory impact testing consisted of four (4) stainless-steel panels, one un-reinforced and three reinforced. These panels were tested using DOE Protocol 5 at Texas Tech University (TTU). The laboratory samples of honeycomb and epoxy were tested. The samples consisted of 4”x4” coupons for 1/8” and ¼” honeycomb density. These were tested for compression and deflection was measured. Assembly was performed in accordance with a honeycomb pattern of 1-layer, 2-layers and 3-layers.
Laboratory tests were performed on the glass fiber reinforcement material and epoxy. The FEM was performed using the software Abaqus. Finally, theoretical CKE of the panels was evaluated using the empirical formulas, Neilson’s, SRI’s, Greenstreet’s and Linderman’s equations to relate to deflection. Gerard’s theory of adding protective layers to reduce CKE appear to be valid. The thickness varies for amount of energy to be absorbed.
The exact formula for CKE is ever eluding. SRI’s formula appears to be the most accurate at this date and time. The sample tests were evaluated, and the deflection was compared to the empirical deflection, and Kunimoto and Yamada’s formulas . It was determined that the honeycomb post installed system may absorb 5.7% to 10.3% CKE depending on the density of the honeycomb, and approximately 1.5% to 60.5% deflection depending on the number of layers or height of the honeycomb.