Legal
Cases
Engineering Cases
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| Steel
Tube Chair O'Donnell Consulting Engineers was requested to perform a failure analysis on a chair that had failed when a 180 pound individual sat down. The evaluation was accomplished using generally accepted engineering design calculations and modern finite-element elastic-plastic large-deflection three-dimensional computer analyses. The failure was due to gross plastic deformation of the material in the bend, which had been deformed during fabrication. The failure occurred when the bending moment applied to the tube exceeded its plastic moment capacity. A three-dimensional finite element analysis was performed to evaluate the structural integrity. The results were compared to the relevant American National Standard, requiring that dynamic loads be included in the structural adequacy of such chairs. The results showed that the chair did not meet these requirement in the “as-built” condition, and was structurally defective per this American Standard. |
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| Large
Diameter Ductwork During operation of a ferro-silicon furnace in Washington State, a nine foot diameter duct failed. This duct carried exhaust from furnace stacks to a baghouse. It was made of one-half inch thick low alloy steel. The failures were predominantly located at the duct supports. Stress analysis and material evaluations showed that the cause of these failures was low cycle thermal fatigue. O'Donnell redesigned the ductwork and support system to reduce the amount of constraint on the duct. The rebuilt system has been operating successfully for many years. O'Donnell later evaluated the work of the original designer and the depositions of witnesses, and provided legal testimony, resulting in a $7.4 million verdict on behalf of the claimant. |
| Ore
Unloader A large ship rammed an ore-unloader at a pier in Trinidad. The 305 ton crane-like device was pushed against a conveyor structure and overturned into the sea on the far side of the pier. Insurance covered the unloader for collapse, but not for collision or overturning. The insurance carrier held that the unloader had not collapsed, but had overturned. O'Donnell investigated the accident. In Common Pleas Court, O'Donnell explained collapse from an engineering point of view, and then traced the progress of the unloader from impact, through translation across the pier, to bending across the conveyor. Damage was defined at each step and it was shown that the forces necessary to do the damage were present. The jury found in favor of the owner for the full amount it was seeking, the replacement cost of the unloader plus interest, $3.1 million. |
| Propane
Pump A propane pump explosion killed one worker and injured three others at a central Ohio factory. The pump was being used to charge aerosol cans with propane propellant at high pressure. The accident occurred when gas leaked past the pistons in the pump. Originally, the pump was built with metal pistons that wore rapidly against the seals. They were replaced with ceramic seals. Designed to pump mud, the ceramic components eventually cracked and loose pieces fell away, causing a massive leak. After examining the crack pattern and characterizing the ceramic material, O'Donnell engineers theorized that the cracking was due to the sudden chilling of the outer ceramic surface. Finite element stress analysis and testing confirmed the opinion. O'Donnell performed an investigation at the request of attorneys, who represented the workers. Based on the O'Donnell findings, four separate cases were settled out-of-court. The plaintiffs received a substantial payment in each case. |
| Gas
Well Pipe O'Donnell evaluated a pipe rupture resulting from a gas well accident in which a worker lost a leg at a plant, north of Pittsburgh. The injured well tender, whose leg was severed below the knee, was initiating a "post-fracking" procedure-blowback operation to release pressure in the capped well-at the time of the mishap. When the main valve was opened, the pipe ruptured due to water hammer. The pipe, set off center, broke loose and whipped around, striking the well tender. O'Donnell engineers, conducting the evaluation on behalf of the worker, found that the pipe did not fail because of faulty material or construction. Our engineers also learned that the fracking subcontractor, after finishing his work at the site failed to issue sufficient instructions to the well tender concerning the potentially dangerous procedure. An out-of-court settlement was negotiated in favor of the worker. |
| Conveyor
System A West African bauxite company was awarded $16 million in a U.S. District Court after a tippler building sustained severe structural damage. Bauxite was dropped twenty-two feet from rail cars onto the conveyor of a crusher system in the tippler building. The conveyor system and concrete support beams were most seriously affected. O'Donnell engineers determined that the impact loading of the bauxite boulders weighing up to ten tons had been grossly underestimated in the design of the building. They concluded that the structure had been under-designed for the anticipated and applied loads. |
| Air
Tank O'Donnell engineers performed extensive testing and analysis that led to an out-of-court settlement after a ruptured air tank caused a workman to lose a leg in Corpus Christi, Texas. The tank, with a maximum allowable working pressure of 150 psi, was intended to energize an air starter for diesel-powered oil well test equipment. After thoroughly examining the tank and reviewing the circumstances surrounding the accident, O'Donnell engineers became convinced the tank exploded while a 2,000 psi nitrogen bottle was being used to pressurize it. According to the evidence, the safety relief valve was isolated while the tank was being energized. O'Donnell, after performing destructive testing of more than twenty tanks, demonstrated that failure likely occurred at more than three times the maximum allowable working pressure. A modest out-of-court settlement was reached between the tank manufacturer and the injured workman. |
| Compressor
Valve Cover An employee was killed and another suffered serious injuries at an Alabama chemical plant when a valve cover failed on the 1350 psi stage of an Ammonia Compressor. Under a law existing only in Alabama, the injured worker filed suit against his co-employees alleging improper maintenance of the equipment. O'Donnell engineers conducted an examination that showed threads had been stripped from several nuts. As a result, the valve cover lifted and the remaining sound studs and nuts bent and broke. Transient temperature analysis of the valve body and the water-cooled compressor case showed the valve body reached operating temperature significantly faster than the casing. Consequently, the valve body expanded to a greater length during heat-up, applying an additional, unanticipated load to the studs and nuts. The additional load was insufficient to cause the nuts to fail, but caused failure in the weaker nuts. The results of the analysis were presented by an O'Donnell engineer in a deposition. The defendants later contributed a small portion to an out-of-court settlement, the larger portion of which was paid by the compressor manufacturer. |
| Bellows An engineer was seriously burned when a thirty-nine inch expansion joint ruptured while workman were performing temporary repairs at a Texas refinery. The ruptured bellows spilled hot catalyst from a fluidizer catalytic cracking unit on the deck which the engineer had to cross to reach safety. The plaintiff alleged that the selection of Type 321 stainless steel by the process designer was unsound, and led to the rupture. O'Donnell was retained to establish why the bellows failed. We found that the stainless steel had not been heat-treated properly during the making of the steel itself and it was sensitized during fabrication and made susceptible to corrosive attack. The case settled out of court, with our client, the process designer, assessed a small portion of the settlement. |
| Process
Vessel For a major food processing company, O'Donnell engineers analyzed the failure of a horizontally mounted low pressure process vessel. The sequential failure of several of the nuts holding the closure head caused it to blow off, seriously injuring a worker. A review of the original design showed that the vessel had not been built with the number of nuts and swing bolts shown on the drawings or on the Manufacturer's Data Report. Metallurgical analysis of the nuts which had failed showed that they were fabricated of weaker material than that originally specified. Information provided by the operating personnel indicated that several of the nuts were generally not used because of inconvenient access. A finite element analysis of the closure head accounted for the maldistributed nuts. These errors taken together exactly used up the safety-factor of five required for pressure vessel bolting design. |
| Turbine
Exhauster O'Donnell Consulting investigated an accident involving a turbine exhauster, which is a high speed, three-stage centrifugal compressor, used to pump exhaust gases out of a coke oven battery. All three compressor stages are located on the same shaft and housed in the in a common casing. The third stage compressor suffered severe damage, and caused subsequent damage to the facility. O'Donnell performed finite element, engineering analysis, metallurgical, and material testing on the disk and blades. It was concluded that small flaws that had been detected earlier had not been correctly evaluated, and were growing to critical size during normal operating conditions. As the crack grew, the stresses in the disk increased - to the point of disk rupture. |
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| Marine
Air Compressor System When an air compressed system used to control the engine and steering controls for a marine transport barge failed, O'Donnell Consulting Engineers performed an extensive analysis of the system. It was determined that the system contained a defective safety valve which was the primary root cause for the system failure, which caused a collision with another vessel. The valve had a latent defect exonerating the ship owner per Maritime Law. |
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Heat
Exchanger Analysis |
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| Space
Telescope O'Donnell Consulting Engineers evaluated the nature of vibratory conditions in the framework supporting the Hubble Space Telescope. Combined analyses and tests showed that conditions were due to second order shortening of the transverse bracing members not found by conventional computer analysis. The vibration problems were then solved using lateral restraints on the transverse members. |
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| Tank
Welds O'Donnell Consulting Engineers performed structural analysis on imperfect welds in an accumulator tank. Metallurgical evaluations were performed in addition to finite element analysis. OCE determined that the welds met Code Safety Margins, and were able to withstand the anticipated environmental and vibratory loading conditions. |
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| Pressure
Vessel Recertification O'Donnell completed a seven-year program to create the equipment safety program for pressure vessels and pressure systems at the NASA-Lewis Research Center. Some of the vessels and systems at Lewis are over forty years old and were a part of the original NACA installation. O'Donnell: (1) obtained design documentation and service records; (2) performed stress, fatigue and fracture analyses to establish regions to be subjected to nondestructive examination; (3) performed nondestructive examination of selected regions and features; (4) performed repairs or analysis to demonstrate the permanent or temporary acceptability of defects; (5) defined the conditions and lifetime for system recertification, and the cyclic interval at which the next inspection is necessary and (6) established areas requiring repair and recommending repair and or replacement based on cost effective analysis. This process costs approximately 15% of the cost of replacement, and the necessary down-time is minor; so there is a major economic incentive for recertification rather than replacement of systems and components. O'Donnell has extensive experience in the recertification process. This evaluation of vessels and piping systems included radiographic, dye penetrant, ultrasonic, magnetic particle and visual inspections to establish soundness of base material and of weldments. Where indications were found, they were characterized and analyzed as appropriate to establish whether the defect is growing or is arrested. O'Donnell also defined the remaining useful life of the item or established specific methods of repair that could be accomplished with minimum impact on operations and at minimum cost. O'Donnell Consulting has performed these services at other major industrial plants. |
| Threaded
Closure Failure O'Donnell Consulting Engineers investigated the cause of an accident due to a failed threaded closure on a wellhead. Through metallurgical evaluations, material testing, and engineering analysis, it was determined that the cast iron nut had failed due to |
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| Panel
Coil Failure of panelcoil components in a large sterilizer was investigated. A failure specimen was examined, and it was determined that the cracking was due to fatigue. This observation led to an investigation of the possibility of the failure being caused by vibration due to the rotating agitator. Bounding calculations indicated that the panels possessed natural frequencies between 8 and 100 Hz. The forcing frequency of the six-bladed agitator was 15 Hz and vibration was therefore identified as the most likely culprit. Concurrently, finite element dynamic methods were used to established a natural frequency to account for the immersion of the panel in water, the frequency was close to 15 Hz. The two independent analyses both demonstrated the failure was induced by fatigue. Locations were provided for panelcoils supports to eliminate the lower modes of vibration. O'Donnell personnel provided further guidance to assure the adequacy of welding processes and welding materials to achieve modifications that subsequently performed reliably in service. |
| Coolant
Injection Plate During a shutdown of the Kuosheng 1 plant, Taiwan, operation of the LPCI system for normal shutdown caused failure of an LPRM. Testing by G.E. in their (HF)2 facility duplicated the failure, which has been attributed to flow-induced vibration of the LPRM. G.E. devised a flow-deflector to prevent cross-flow from the LPCI across core components. This deflector had to be installed in Grand Gulf very quickly to avoid delay in fuel loading. In order to increase assurance that the design, construction, and installation of the deflector plate were proper, Mississippi Power & Light Company asked O'Donnell to review the problem and the proposed solution. O'Donnell analytically determined that the fatigue usage factor, pump-induced vibration, low-pressure injection system head loss, fluence at welds, and the diaphragm connection of the LPCI line to the shroud were adequate. Subsequent testing confirmed the adequacy. |
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Boiler
Tube Analysis |
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| Elevated
Temperature Design Criteria For an international group of sponsors, O'Donnell conducted a program for development of elevated temperature structural design criteria. Many of the elevated temperature design criteria now part of the ASME Boiler and Pressure Vessel Code were developed under this program. The work included development of criteria and methods for fatigue evaluation, ductile failure mode analysis, inelastic analysis of complex components, and design for cyclic service at elevated temperature. Some of the newer methods are based on the use of results of purely elastic analysis to perform simplified inelastic analysis of structures in elevated temperature service. The work also included the development of design criteria for acceptance of cracks in structural components subjected to cyclic loading at elevated temperature. The program was sponsored by major organizations in the United States including Oak Ridge National Laboratories, Westinghouse Electric, Rockwell International, and General Electric. |
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Sprinkler
Analysis |
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| NASA
Space Shuttle Main Engines O'Donnell developed an analytical procedure for predicting thrust chamber life limited by the small number of firings. In an operating rocket thrust chamber the hot-gas-wall ligaments separating the coolant and combustion gas are subjected to pressure loading and severe thermal cycling. The resulting stresses cause plastic straining resulting in incremental bulging of the ligaments during each firing cycle. This mechanism of creep ratcheting was analyzed considering combined bending and membrane loading. The incremental permanent deflection and progressive thinning near the center of the ligaments was evaluated. Creep and tensile instability were identified as the limiting mode of failure. Results of these analyses compared favorably with available experimental data and allowed design changes which extended the design life. |
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| Boiler
Tubes O'Donnell Consulting Engineers have evaluated the remaining useful life of numerous boiler tubes. These evaluations were based on the results of metallographic analysis of internal and external corrosion, creep damage evaluations and the remaining life for the operating pressure/ temperature conditions. |
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| Wheel
Lugs O'Donnell Consulting Engineers performed an independent review of the cause of an automobile accident. The analysis determined that excessive torque had been applied to the wheel lug nuts, thus decreasing the fatigue life of the wheel lugs. |
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| Pressure
Vessels O'Donnell Consulting Engineers performed an independent structural analysis of pressure swing absorption vessels. This evaluation was to quantify vessel fatigue life and recommend to continue in operation, repair, or replace the vessels. |
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| Valve
Analysis O'Donnell Consulting Engineers performed failure analysis of a butterfly valve used to hydrotest a pressure reduction system. Various interdependent factors were found to be the cause, including inadequate valve stud materials. |
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| Offshore
Equipment O'Donnell Consulting Engineers performed a structural analysis of a power generation unit base skid for application on a floating storage and offloading facility. Comprehensive finite element analyses were performed for various loads, including the effects of sea, wind, and ice conditions. Fatigue analyses were also performed to determine structural life. |
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| Playground
Equipment O'Donnell Consulting Engineers performed an independent review of the assembly and weld procedures for the manufacture of playground equipment. |
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| Bracket
Failure Analysis O'Donnell Consulting Engineers performed a comprehensive failure analysis of an industrial lift hook bracket assembly. Three-dimensional finite element analyses determined that stresses in the hook varied as lifting configurations were altered. The results determined that a bracket redesign was required to handle all of the various loading conditions. |
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| Storage
Tank O'Donnell Consulting Engineers performed inspection and metallurgical testing of a storage tank to determine the amount and rate of corrosion on the tank. Remaining wall thicknesses were evaluated and recommendations for repair were made. |
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O'Donnell Consulting Engineers performs a range of engineering design and analysis services-
- Stress/ Structural Analysis
- Thermal Transient Analysis
- Fatigue & Vibration Analysis
- Buckling/ Instability
- Creep Analyses
as well as forensic engineering services-
- Failure Analysis & Metallurgy
- Engineering Expert Witness
We are experts in the fields of materials, metallurgy, mechanical engineering, civil engineering, and chemical engineering. We have helped many clients solve complex problems allowing them to increase production performance, and become more cost-efficient.
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