Structural Analysis

Finite Element Analysis of Ship Propeller Hub

Bird Johnson Company, Walpole, MA

Summary of Statement of Work:
DBA was tasked to perform a nonlinear(contact), structural finite element analysis (FEA) of an existing controllable pitch propeller. The purpose of the analysis was to help determine the cause of premature wearing of internal components. The presence of detrimental corrosion and cracking on the bearing surfaces forced the US Navy to replace propellers on its Guided Missile Destroyer fleet more often than planned.

DBA created a solid model assembly of the blade, hub and internal components to simulate the actual hardware, including clearances and fits. The FEA analysis revealed excessive deflection of the hub and provide design engineers with the quantitative results necessary to redesign the existing hub.

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Structural Analysis of a Boat Trailer

Triad Trailers, New Milford, Connecticut

Summary of Statement of Work:
Design By Analysis, Inc. (DBA) performed structural analysis of a boat trailer to predict the margin of safety provided by the existing design.

The complete trailer structure was included in a finite element model to determine loads and stresses in all beam members. Weld connections were also analyzed. Recommendations were made to improve the strength of certain connections.

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Finite Element Stress Analysis of Plastic Flange

Walbro Automotive Corporation, Meriden, CT

Summary of Statement of Work:
DBA was contracted to perform finite element stress analysis in support of the redesign of a recessed flange for Walbro Automotive Corporation.

DBA analyzed two parts that were similar. One of the parts had been strengthened by placing ribs in a critical area. As a result, DBA was able to recommend and verify a rib pattern that would lower the stress in the critical area by a factor of four.

DBA completed the first two analyses in two working days and provided their conclusions in time to change the design a third time. A final analysis was turned around in one day following receipt of the part after its final design iteration was completed.

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Stress Analysis of a Polyethelyne Molded Structure

Springfield Mold Works, Westfield, MA

Summary of Statement of Work:
Design By Analysis, Inc. (DBA) performed a finite element stress analysis on a polyethylene molded structure.

Multiple design configurations with various boundry conditions and load cases were analyzed. Based on the results of the analysis, recommendations were made for the re-design of the structure.

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Nonlinear Contact Analysis of S61 Main Rotor Shaft

Sikorsky Aircraft, Stratford CT

Summary of Statement of Work:
As a portion of a project for Sikorsky Aircraft, DBA was contracted to perform a nonlinear contact analysis of a section of the S61 Main Rotor Shaft/Planetary Assembly.

The contact areas included the dowel pin and holes in the Main Rotor Shaft along with the Planetary, the Main Rotor Shaft Flange and the Planetary Flange. The deliverables included plots of principle stress results, maximum deflection and accuracy of predictions.

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Dynamic Analysis of Gun Turret

Kollmorgen Electro Optical, Northampton, MA

Summary of Statement of Work:
DBA performed random vibration and dynamic analysis on a vehicle-mounted turret.

Random vibration analysis simulated vehicle travel effects using ASD (Acceleration Spectral Density) specifications from MIL-STD-810. Dynamic analysis predicted turret response to recoil.

Analytic results led to design improvements in various components comprising the turret assembly

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