Simple Method For Repair Research Articles

Effectiveness of repairing yielding anchor rods in exposed column bases in steel structures

AbstractOne of the features of Japanese structural steel design is an economical design option for yielding exposed column bases before first‐story columns, namely weak‐base/strong‐column design, which is unlike the strict capacity design for column bases. This study aims to develop a repair methodology that identifies damage states of the yielding column bases and anchor rods, and selects appropriate repair/retrofit methods. As a standard repair method for damaged exposed‐type column bases, the applicability and effectiveness of the re‐tightening process of anchor rods need to be examined. This study first reviews the literature on standard retrofit techniques for column bases and required deformation capacity of ductile anchor rods. The threaded anchor rod deformation capacity with different steel grades and screw threads commonly used were tested to clarify the required ductility. To clarify the reparability of exposed column bases, numerical models of four‐ and six‐story steel moment resisting frame buildings were developed and validated by shaking table test results. The results show that this simple repair method was proven to be effective through the test program and numerical analysis and it's not always applicable for standard anchor rods assumed for pin or fixed column bases designed to remain elastic. Finlly, a repair methodology and flow chart that identifies the damage states of anchor rods and selects appropriate repair/retrofit methods for the exposed steel column base was suggested and applied to the simulation results.

A Simple Repair Method of Fatigue Cracks Using Stop-holes Reinforced with Wedge Members

A Simple Repair Method of Fatigue Cracks Using Stop-holes Reinforced with Wedge Members

Paper Review of “A Simple Repair Method of Fatigue Cracks Using Stop-holes Reinforced with Wedge Members”

Paper Review of “A Simple Repair Method of Fatigue Cracks Using Stop-holes Reinforced with Wedge Members”

THE ANTI-CORROSIVE REPAIR METHODS FOR DEGRADED WEATHERING STEEL BRIDGES

The existing rust with heavy amounts of salinity or anti-freezing agents on the weathering steel bridge surface can lead to serious durability issues. In the event that the anticorrosion functions of weathering steel bridges do not perform satisfactorily, it is necessary to eliminate the cause or to consider the repair coating and the life extension process. In order to achieve the expected life of the repair coating, it is important to perform the correct surface treatment, appropriate surface preparation (near-white blast cleaning, ISO standard Sa2 1/2 equivalent), and the certain removal of rust containing salinity (50 mg/m2 or below). This study provides state-of-the-art techniques on repair method, which is two repair coating methods and one simple repair method for weathering steel bridges. In 2015, some repair methods, with considerable effectiveness, were carried out to actual weathering steel bridges with undesired rust generation. The investigation of three years after repair coating shows that both repair coating film is confirmed to exhibit good corrosion resistance. The weathering steel surface repaired by simple repair method is also in a good state.

A simple repair method of fatigue cracks using stop-holes reinforced with wedge members: applicability to reinitiated cracks and effects of an anti-fatigue smart paste

ABSTRACT A simple method of repairing fatigue cracks using stop-holes reinforced with wedge members, that was previously proposed by the author, has been examined for the case of reinitiated cracks. By using this method, the stress intensity factor range around a reinitiated crack tip is expected to be reduced by the wedge load effect of the wedge members. The chief advantages of this method are that the repair work can be easily performed from only one side of a cracked structure, and that the wedge member can be set so adaptive as to maintain the wedge load automatically and effectively as the reinitiated crack grows. Specifically, slope-type wedge members have been adopted, and an adaptive mechanism of the wedge member has been devised using a pulley and a wire-type displacement metre. Fatigue tests were performed on a steel plate specimen with a drill hole and a notch, and validity of the above repair method was experimentally examined using both of simple and adaptive wedge members. In addition, an anti-fatigue smart paste, which consists of fine alumina particles and silicone grease, was applied to the periphery of the drill hole, and its effects on automatic restraint and visual detection of crack growth were investigated. FE analyses using contact elements were also carried out for a comparative study. As a result, it was found that the strain range on the specimen side is reduced to 44.0 % and the fatigue life is prolonged by 12.4 times by application of the adaptive wedge member as compared with the case of the conventional stop-hole. As for the anti-fatigue smart paste, it was found that the fatigue life is further prolonged by about three times as compared with the case of the adaptive wedge member and the paste has an evident function to facilitate visual detection of cracks.

A simple repair method of fatigue cracks using stop-holes reinforced with wedge members

ABSTRACT A simple method of repairing fatigue cracks using stop-holes reinforced with wedge members has been newly proposed. By using this method, the stress range at the stop-hole edge is expected to be drastically reduced by the wedge load effect of the wedge member. The chief advantages of this method are that the repair work can be easily performed from only one side of a cracked structure and that the wedge member can be set so adaptive as to maintain the wedge load automatically and effectively even after the structure around the stop-hole is subjected to some excessive tensile loads and the stop-hole is plastically deformed. Specifically, slope-type wedge members have been newly designed and optimized, and an adaptive mechanism of the wedge member has been devised using a pulley, a string and a weight. Static loading tests and fatigue tests were performed on a steel plate specimen with a slit and a drill hole, and validity of the above repair method was experimentally examined using both of simple and adaptive wedge members. FE analyses using contact elements were also carried out for a comparative study. As a result, it was found that the stress range at the stop-hole edge is reduced by more than 60 % and the fatigue life is prolonged more than 20-fold by application of the adaptive wedge member as compared with those in the case of the conventional stop-hole. It was also shown that application of the simple wedge member is limitedly effective when the wedge part is held on the specimen and the applied load range is lower than a certain level.

A Simple Repair Method of Fatigue Cracks Using Stop-holes Reinforced with Wedge Members

A simple method of repairing fatigue cracks using stop-holes reinforced with wedge members, that was previously proposed by the author, has been examined for the case of reinitiated cracks. By using this method, the stress intensity factor range around a reinitiated crack tip is expected to be reduced by the wedge load effect of the wedge members. The chief advantages of this method are that the repair work can be easily performed from only one side of a cracked structure, and that the wedge member can be set so adaptive as to maintain the wedge load automatically and effectively as the reinitiated crack grows. Specifically, slope-type wedge members have been adopted, and an adaptive mechanism of the wedge member has been devised using a pulley and a wire-type displacement meter. Fatigue tests were performed on a steel plate specimen with a drill hole and a notch, and validity of the above repair method was experimentally examined using both of simple and adaptive wedge members. In addition, an anti-fatigue smart paste, which consists of fine alumina particles and silicone grease, was applied to the periphery of the drill hole, and its effects on automatic restraint and visual detection of crack growth were investigated. FE analyses using contact elements were also carried out for a comparative study. As a result, it was found that the strain range on the specimen side is reduced to 44.0% and the fatigue life is prolonged by 12.4 times by application of the adaptive wedge member as compared with the case of the conventional stop-hole. As for the anti-fatigue smart paste, it was found that the fatigue life is further prolonged by about three times that in the case of the adaptive wedge member and the paste has an evident function to support visual detection of cracks.

Simple Repair Method to Stop Water Leakage from Joints of Small-scale Concrete Canals

Simple Repair Method to Stop Water Leakage from Joints of Small-scale Concrete Canals

Investigation of composite repair method by liquid resin infiltration

'Conventional' or certified repair procedures for impacted composite structures (i.e. patches) are time consuming, and must be performed by highly qualified staff. In this paper, a cost effective and simple repair method by liquid resin infiltration is studied. As damages on aircraft structures are generally due to impact, this kind of damage is characterised and compared to quasi-static indentation with ultrasonic inspection and micrographic cuts. The repair by liquid resin is used to fill in the very special damage pattern region organised as a crack network (delamination and transverse cracks). In order to study this new repair method, an experimental set-up has been manufactured and different configurations have been studied. Mechanical testing (CAI, DCB and ENF) was then performed to evaluate the strength of this repair. As good results were achieved, further exploration under complex loading should be performed to ensure the quality of the repair for an industrial application.

Development of a Simple Repair Method Using Structural Bonding Tape to Stop Water Leakage from Joints of Small-Scale Concrete Canals

Development of a Simple Repair Method Using Structural Bonding Tape to Stop Water Leakage from Joints of Small-Scale Concrete Canals

Endoscopic cranioplasty with calcium phosphate cement for pterional bone defect after frontotemporal craniotomy: technical note.

Postoperative pterional depression is a minor but unpleasant sequela of frontotemporal craniotomy. We developed a simple method for repair of this condition with the use of an endoscope and calcium phosphate cement. The cranial defect was approached by means of endoscopic visualization through a small incision within the hairline. The defect was repaired with an injectable calcium phosphate cement. The bone defect was easily accessed and readily repaired in all five patients. No adverse reactions to the implant were observed. Satisfactory cosmetic results were obtained in all patients treated with the use of this method. This minimally invasive cranioplasty technique proved to be effective for the repair of the postoperative pterional defect.

Free bladder mucosal autograft in the treatment of complicated vesicovaginal fistula.

To describe an effective and simple method for repairing complicated vesicovaginal fistula using a free bladder mucosal autograft. The study included 14 patients with an iatrogenic vesicovaginal fistula after hysterectomy or prolonged obstructed labour. An initial fistula repair had been attempted in 12 patients. All patients were then repaired using a free bladder mucosal graft technique 3-24 months (mean 8) after the fistula was diagnosed. Of the 14 patients 12 had an immediately successful result, with no evidence of leakage, but two required prolonged catheter drainage. Thirteen patients remained dry at the follow-up 3-15 months later. Two patients had stress urinary incontinence and three patients had urinary tract infection. The free bladder mucosal autograft technique is a simple, effective and fast method for vesicovaginal fistula repair. The technique produces an excellent repair of complicated vesicovaginal fistula, and appears to be more physiological and easier to perform than other transabdominal techniques.

Simple Method for Repair of Collateral Ligament Injuries of the Thumb Metacarpophalangeal Joint

Brooklyn, N.Y. The Brookdale University Hospital and Medical Center One Brookdale Plaza Brooklyn, N.Y. 11212–3198[email protected] From the State University of New York, Health Science Center at Brooklyn, and Brookdale Hospital Medical Center. Received for publication September 30, 1999; revised November 18, 1999. Presented at the Residents' and Fellows' Conference, New York Society for Surgery of the Hand, at the Hospital for Joint Diseases, New York City, on May 10, 1999.

Evaluation of repair phase and size tolerance for a phase-shift mask

The conjugate twin-shifter method for alternating phase-shift method provides the flexibility for mask shifter layout, and is applied for both isolated and periodic shifter arrays in conventional i-line positive resist processes. A new mask structure simplifies shifter pattern delineation and reduces the effects of phase defects. The detail of intermediate phase interference has been analyzed by applying the two-dimensional shifter array as the phase defect. The results of this analysis provides the optimum repair element array for the new repair method of phase defects. Then the effectiveness of this simple repair method is examined in the i-line process by using the test arrays that delineated in the XeF2 assisted focused ion beam process.

Versatility of Lumbar Transposition Flaps in the Closure of Meningomyelocele Skin Defects

A simple method for repair of skin defects after neurosurgical ablation of meningomyelocele is described. One or two skin flaps adjoining the defect are elevated, the right based superiorly and the left inferiorly. They are then transposed to cover the dural repair, and the donor site is repaired by a split-thickness skin graft. The ability of these flaps to close defects of all sizes is stressed.

A Simple Method for Repair of Postcatheterization False Aneurysms

A Simple Method for Repair of Postcatheterization False Aneurysms