RBS 철골모멘트접합부의 내진거동평가를 위한 반복재하 실물대(實物大) 실험

이철호,김진호,전상우 한국강구조학회 2002 韓國鋼構造學會 論文集 Vol.14 No.4

paper summarized the results of a full-scale cyclic seismic testing on four reduced beam section (RBS)steel moment connections. Specifically, these tests addressed a bolted web versus a welded web connection and strong versus medium panel zone (PZ) strength as key test variables. with medium PZ strength were designed to promote balanced energy dissipation from both PZ and RBS regions, in order to reduce the requirement for expensive doubler plates. Both strong and medium PZ specimens with welded web connection were able to provide suficient connection rotation capacity required of special moment-resisting frames. On the other hand, specimens with bolted web connection performed poorly due to premature britle fracture of the beam flange at the weld access hole. Unlike the case of web-welded specimens, specimens with cheaper bolted web connection not transfer the actual plastic moment of the original (or unreduced) beam section to the column. No fracture occurred within the beam groove welds of any connection in this testing program. If fracture within the beam flange groove weld is avoided by using quality welding procedure as in this study, the fracture issue tends to move into the beam flange base metal at the weld access hole. Supporting analytical study was also conducted in order to understand the observed base metal fracture from the engineering mechanics perspective. 본 논문은 4개의 RBS 철골모멘트 접합부에 대한 반복재하 실물대 (實物大) 실험결과를 요약한 것이다. 주요 실험변수는 기둥과보의 접합방식 (볼트접합 대 용접) 및 패널존의 강도 (강한 패널존 대 중간강도 패널존 )이다. 중간 패널존 강도를 갖는 시험체는 패널존과 RBS 영역 모두에서 균형잡힌 방식으로 에너지가 소산되도록 고려하여 설계된 것으로 패널존 보강비용을 줄이고자 시도한 경우 이다. 보웨브가 용접으로 접합된 경우의 시험체들은 특별연성모멘트골조에 요구되는 충분한 접합부 회전성능을 보여 주었지만 , 웨브를 볼트로 접합한 시험체들은 스캘럽을 가로지르는 보플랜지의 조기 취성파괴로 인해 열등한 내진성능을 노출하였다 . 보웨브를 볼트로 접합하면 비용을 줄일 수 있으나 원래 보단면의 전소성모멘트를 기둥에 전달하기에 어려운 것으로 나타났다 . 본 연구에서 적용된 것과 같이 양질의 용접시공에 의해 일단 그루브 용접부 자체의 취성파괴 문제가 해결되고 나면 , 용접접근공내에 위치한 보플랜지 모재의 파단이 다음의 문제로 대두됨을 알 수 있다 . 용접접근공 내의 보 플랜지 파단문제를 역학적인 측면에서 이해하는데 도움이 되는 해석적 연구도 수행되었다 .

리브로 보강된 철골 모멘트 접합부의 내진거동에 관한 실험적 연구

이철호,정종현,이재광,오명호,구은숙 한국강구조학회 2002 韓國鋼構造學會 論文集 Vol.14 No.4

simple design method for seismic steel moment connections has been recently proposed basedon the equivalent strut model. An experimental program was implemented to verify the proposed design method, as wel as develop the schemes that wil prevent cracking at the rib tip where stress concentration was evident. All specimens designed using the proposed method were able to develop a satisfactory connection plastic rotation of 0.04 radian. In addition to rib reinforcement, slight beam flange trimming pushed the plastic hinging and local buckling of the beam away from the rip tip and effectively reduced cracking potential at the rib tip. Using strain gage readings, the strut action of the rib and resulting reverse shear in the beam web were also experimentally identified. 리브로 보강된 철골 모멘트 내진접합부에 대한 실용적이고 간단한 설계법이 등가스트럿 모델을 바탕으로 최근에 제안된 바가 있다. 본 논문에서는 제안된 설계법을 검증하고 응력집중에 의한 리브 단부의 균열방지 방안을 모색하기 위한 실험결과를 기술 하였다. 제안된 설계법에 의해 설계된 모든 실물대 시험체는 접합부의 소성회전각이 0.04 (radian)에 이르는 뛰어난 내진성능을 발휘하였다 . 접합부를 리브로 보강함과 동시에 보의 플랜지 일부를 잘라내어 보의 소성힌지와 국부좌굴의 발생위치를 리브의 끝단으로부터 보 안쪽으로 약간 이동시킴으로서, 리브단부의 균열발생을 효과적으로 제어할 수 있음을 실험적으로 확인하였다 . 또한 리브의 스트럿 작용과 이로 인한 보 웨브에서의 전단역전을 스트레인 게이지 계측을 통하여 실험적으로 입증하였다 .

가열방법에 따른 고기풀 젤의 형성기작과 물성학적 행동변화

이철호,최원석 한국산업식품공학회 1998 산업 식품공학 Vol.2 No.2

새로운 식품가공기술인 옴(ohm)가열을 통한 고기풀 젤 형성기작과 관련된 주요 단백질 분자간 가교결합(cross-link)형태의 변화와 이에 따른 젤의 물성학적 행동변화를 기존의 가공방법인 수욕가열과 비교, 검토해 보고자 하였다. 먼저 고기풀 젤 형성온도대인 10℃에서 90℃까지의 옴 가열 및 수욕가열의 온도 특성을 살펴본 결과, 옴 가열의 경우가 수욕가열보다 10-90℃의 고기풀 젤화시간과 단백질 분해효소드의 최적 활성 온도대인 50-70℃를 통과하는데 드는 시간이 단축되었으며, 반면에 소수성 결합과 transglutaminase에 의한 교차결합이 주로 일어나는 10-30℃의 온도대의 통과시간은 오히려 옴가열의 경우에서 연장되었다. 이런 가열특성이 고기풀젤의 물성에 미치는 영향을 알아보기 위하여 옴 가열한 고기풀 젤과 수욕가열한 고기풀 젤들간의 물성의 차이를 creep/recovery test를 통해 비교한 결과 옴가열한 젤이 Hookean body의 탄성율과 Newtonian body의 점도가 각각 3.03 kPa, 2.94×10^6 Pa·S로 수욕가열한 경우의 2.51 kPa, 2.94×10^6 Pa·S보다 크게 타나타 옴 가열 고기풀젤이 보다 견고하고 탄력적이며, 덜 유동적인 물성을 지니는 것으로 나타났다. 가열방법에 따라 나타난 고기풀 젤의 물성차이를 분자간 결합양상의 차이로 설명하고자 젤 형성시 중요한 역할을 하는 결합에 영향을 주는 수소결합 저해제인 guanidine hydrochloride(G-HCI), 소수성결합에 영향을 주는 sodium dodecyl sulfate(SDS)그리고 S-5 결합에 영향을 주는 β-mercaptoethanol(β-ME)을 100mM농도로 고기풀에 첨가하여 creep/recovery test를 통해 가열방법에 따른 이들 젤의 점탄성 성질변화를 조사하였다. G-HCI을 첨가시 앞선 실험결과에서 보여주었던 옴 가열과 수욕가열시의 고기풀 젤들간의 물성차이를 비교적 그대로 유지하여 가열방법에 따른 물성의 차이에 수소결합의 영향은 그리 크지 않은 것으로 생각된다. 반면에 SDS를 첨가한 결과 기존에 보였던 젤들간의 물성차이를 크게 감소시켰으며 β-ME의 첨가시에도 가열방법에 따른 젤 강도의 차이가 감소되어 소수성 결합과 disulfide결합이 가열방법에 따른 고기풀 젤의 물성차이에 중요한 역할을 하는 것으로 생각된다. Mechanism for the changes of rheological property of surimi gel by different heating methods, ohmic heating and water-bath heating, was examined by using creep/recovery test. In ohmic heating, time for gelling surimi fom 10℃ to 90℃ and for heating it from 50℃ to 70℃, which is ranged for optimal proteolytic activity of proteases was need less than that in water-bath beating. But between 10℃ and 30℃ which are important ranges for hydrophobic interaction and cross-linking by transglutaminase, time for ohmic heating was needed more than that for water-bath heating. Elasiticity of Hookean body and viscosity of Newtonian body for ohmic heated surimi gel were 3.03 kPa and 3.51×10^6 Pa·s, respectively, which values were greater than those of water-bath heated gel, 2.51 kPa and 2.94×10^6 Pa·s. Surimi gels which contained 100 mM guanidine hydochloride (G-HCl), sodium dodecyl sulfate (SDS) and β-mercaptoethanol (β-ME), respectively, were treated by different heating methods, ohmic beating and water-bath heating. The rheological differencies between gel contains G-HCl and not G-HCl, which were heated with different methods, had similar tendency. While rheological differencies of gels contain SDS and β-ME, respectively, which were heated with different methods, were less than those not contain SDS and β-ME. Presumedly the reations of dusulfide bond and Hydrophobic interaction during gel formation were different in ohmic heating and water-bath heating, respectively.

밀턴의 가면극 연구

이철호 한국밀턴학회 2000 중세근세영문학 Vol.10 No.1

Milton wrote Comus, in the first place, as a kind of housewarming entertainment. But when the house is Ludlow Castle and the new occupier the Earl of Bridgewater, who is moving into his official residence as Lord President of Wales, it is not a usual housewarming or entertainment, but a public statement of the important principles of his provincial jurisdiction. As Milton knew the Egertons belonged to a group long recognized for their tacit support of the Puritan cause and the Reformation in England, the work naturally tends to have considerable public and political reference, as well as moral and religious interest. After the work was first put on the stage at the Castle in 1634, Milton continued to revise it though he had no intention to perform it another time. As a result, Milton's Comus has come down to us in five versions from his own lifetime and in later adaptations. They are: Trinity Manuscript(TM), Bridgewater Manuscript(BM), A Maske of 1637(1637), and A Mask of 1645(1645) and 1673(1673). Here I try to trace the differences among the versions and to connect them to its theme of the triumph of virtue over vice. There are two major differences among these five versions. The first fundamental difference arises between BM and all other versions by reason of its omitting six passages that appear in TM. The omissions have usually been taken as cuts, probably made by Lawes, to shorten the time of performance or lighten the young actress's role. They could, however, have been made by Milton while he thought of them as passages which were to be left out for performance's sake. The second difference exists between 1637, which is much alike to 1645 and 1673, and TM. The printed text of 1637 adds the Lady's powerful defence of chastity in her last speech to Comus and amends the epilogue, adding in particular the description of the Garden of Adonis where "Celestial Cupid holds his dear Psyche and makes her his eternal Bride." This revision shows that, as the Puritan Revolution went on, Milton wished to change the first idea of negative aspect of virtue to that of positive aspect, which means that the true Christians shall overcome any difficulties by the help of God's Providence working practically in the history. In a word, the constant returning to Comus shows Milton never lost interest in the ideas it discusses. The deepening political crisis had so changed circumstances that he felt it necessary to change the work from an entertainment for a noble family to a poetic drama in which he could justify the divine intervention in the Puritan Revolution.

「리시다스」의 "쌍수의 기계"에 관한 소고

이철호 한국밀턴학회 1999 중세근세영문학 Vol.9 No.2

The confusing crux of the lines 130-31 of "Lycidas" has created a lot of controversy that has, in turn, furthered our understanding of MIlton's poetry, but has failed to explain satisfactorily the image's meaning. Here I want to propose still another 'possible' solution to the crux. The poem can be thought of as a process in which the speaker is trying to find out an answer to the question "Since it must end in death, what good is life?" As Lycidas who dies before his time has given his life to art and pastorship, this question can also be paraphrased as "What boots it with incessant care / To tend the homely, slighted shepherd's trade, and strictly meditate the thankless Muse?"(64-6). The first answer which the pagan god Phoebus makes to this question is comforting but not wholly satisfactory. He argues an immortality of true fame that is rewarded by "all-judging Jove" after death, but it is a fame unconnected with any mortal striving in this world. Peter gives the second answer in which he wags his venomous tongue at the corrupted clergy instead of ensuring the good shepherd's resurrection through Christ's crucifixion. As Peter predicts the "two-handed engine" to them and we have no gloss from Milton, we must consider at least four things, that is, the words themselves, the immediate context of the lines, the broader context of the entire poem and any outside clues. Taking all these things into consideration, we can safely say that Milton may visualize the sword of Michael which the archangel will use to punish the infidels at the Last Judgment. This sword seemed to be suggested to Milton from the sharp two-edged sword which issues from God's mouth (Revelation 1. 16), and after the time started to be ripe for Revolution he also identified it with the protestant movement hewing off the old and hollow tree of papacy.

앤드류 마아블의 "호라티우스풍의 부(賦)" 연구

이철호 한국밀턴학회 1998 중세근세영문학 Vol.8 No.-

Because of the ambivalences of "Horatian Ode" evoked by many ironies and ambiguities, much ink has been spilled over the issue of who is the real hero or of whom Marvell is on the side. I do not wish to add a little ink to the same premises, but I can only suggest in passing that Marvell takes up the position that whether we like it or not, history has to be accepted. Charles I died with dignity; but Cromwell was the instrument of Providence or history. It is clear that he was prepared to accept the triumphant revolution over the king, whose bleeding head was needed as the foundation of Commonwealth. For too many readers the scene of Charles's execution disturbs the center of gravity of the poem. If we do not, however, forget the fact that throughout the poem Marvell wants to put the focus on the historical development, we can safely say that his sympathy for Charles I's personal virtues is outweighed by his admiration for Cromwell who is supported by the historical force and God's will. Marvell's famous phrase "the Cause was too good to have been fought for" does not mean that after the Restoration he rejected the cause of the revolution, but that the war should not have been fought because it need not have been fought, because the victory of Parliament was inevitable, war or not. Though we can read off a little reluctance to the cruelties of the war and the forced power, this poem shows that Marvell was no longer an aristocratic young cavalier but a sound Parliamentarian.

『실락원』에 나오는 마왕의 기이한 세 삽화

이철호 한국밀턴학회 1997 중세근세영문학 Vol.7 No.-

Because Milton wants to make a description of what can't be described, such as the agency of God, Christ, and spirits, he has no choice but to use many similes to magnify Satan whose words and actions are to be guessed by analogy with human behavior. This entails many critical or laudatory opinions. But, when we think that criticism has been conditioned by the moral and political and religious viewpoint of successive generations, most of the different opinions can be understood. The Satanists, living through the French Revolution, tend to regard Satan as both a great poetical creation and an object for moral sympathy. On the other hand, Dr. Johnson and Eliot, taking up the position of different religion and politics, keep on being antipathetic to him and critical to his works. Both parties appear to overlook the fact that though the magnifying similes seemingly illustrate Hell's greatness, they really emphasize the Creation by using another pricking similes of inflated Satan. Milton's "conscious" meaning is obviously to justify God's providence and man's free will. If this meaning could be weakened to some degree by the "unconscious" meaning which results from high-lighting the Devil, his original intention is consistently felt through- out the text by dint of the magnifying and diminishing similes and his aesthetic distance. To pass impartial judgment on Satanists, we must point not only their failure to see Milton's conscious purpose but their new approach to the unconscious realm.

밀턴의 1645년 시집

이철호 한국밀턴학회 1996 중세근세영문학 Vol.6 No.-

As Milton lived through and responded to the most politically and religiously convulsive period in the Britain's entire history, he will not be fully understood if we try to approach him on our own preconceptions. By 1645 he had a considerable reputation as a social controversalist. But he won relatively little fame as a poet, though this had been his one constant ambition. In this respect the publication of Poems (1645) by a man with such a nigh political and social career in such a year - the year of the battle of Naseby where Fairfax and Cromwell defeated the King's forces - cannot have been without political intent or significance. So we can consider this collection both as a poetic autobiography of a man who wants to practice poetry as a public duty and conscience of the age, and as a manifesto which lays claim to a historical and providential authority in the commonwealth.

"L`Allegro" 와 "Il Penseroso" : 詩神과 쟝르 Muses and Genre

이철호 한국밀턴학회 1993 중세근세영문학 Vol.3 No.-

Milton's twin poems, "L'Allegro" and "Il Penseroso", have been much discussed in the light of a variety of taditions-the academic prolusion, the rural excursion, and the argumentative debate-, but their basic relation with classical genre has not been sufficiently noticed. Especially the identity of Mirth and Melancholy not only as classical goddesses but as two speakers' patron goddesses has been overlooked as interpretive guide to the meaning and connection of the companion poems. Milton shows each different kind of genre in epitome by selecting as patroness for "L'Allegro" the most active and social of the 3 Graces, Euphrosyne, and as patroness for "Il Penseroso" the most remote and contemplative of the 9 Muses, Urania. Mirth inspires 'less serious genre' like the lyric, elegiac, and bucolic pastorals, while Melancholy inspires 'more serious genre' such as the intellectual and contemplative idylls. As the speaker of "L'Allegro" makes the whole world of comedy and romance appear in a single figure, Hymen, so the poet of "Il Penseroso" makes the world of Tragedy and Epic in a personified Tragedy. In short, by means of a fusion of the world of classical mythology and the English landscape and social life Milton paints the portraits of the typical elegiac poet, who sings of love and wine, and the typical epic poet, who tackles higher themes and must lead a more ascetic life. The complex difference and similarity between the twin poems must be considered in this respect. Though Milton presents us two different accounts of poetical inspiration, there is no need to choose between the two and to favor the Muses above the Graces or vice versa.

용접 철골모멘트 접합부의 전단력 전달경로의 해석적 검토 ( Analytical Re-examination of Shear Force Transfer in Welded Steel Moment Connection )

이철호,윤태호 대한건축학회 1999 大韓建築學會論文集 : 構造系 Vol.15 No.12