不只(zhi)能夠(gou)防止(zhi)普(pu)通(tong)支(zhi)(zhi)(zhi)撐(cheng)(cheng)拉壓承載力差別(bie)顯著的(de)缺(que)陷(xian)，而且具有金(jin)屬阻尼器的(de)耗能才能，屈(qu)曲(qu)(qu)(qu)約(yue)束支(zhi)(zhi)(zhi)撐(cheng)(cheng)克(ke)制了(le)普(pu)通(tong)鋼支(zhi)(zhi)(zhi)撐(cheng)(cheng)受(shou)壓容(rong)易(yi)屈(qu)曲(qu)(qu)(qu)的(de)缺(que)陷(xian)，不只(zhi)能提(ti)供(gong)有效的(de)抗側剛度，并且具有很好的(de)滯(zhi)回(hui)耗能性能。能夠(gou)在構造(zao)中(zhong)充任"保(bao)險絲",防屈(qu)曲(qu)(qu)(qu)支(zhi)(zhi)(zhi)撐(cheng)(cheng)工作的(de)原理是經過一(yi)定的(de)屈(qu)曲(qu)(qu)(qu)約(yue)束機制，限制撐(cheng)(cheng)受(shou)壓屈(qu)曲(qu)(qu)(qu)，使(shi)得(de)(de)支(zhi)(zhi)(zhi)撐(cheng)(cheng)能受(shou)壓屈(qu)從但(dan)不屈(qu)曲(qu)(qu)(qu)，具有豐滿的(de)滯(zhi)回(hui)曲(qu)(qu)(qu)線。使(shi)得(de)(de)主體構造(zao)根本處于彈(dan)性范圍內(nei)。因(yin)而，屈(qu)曲(qu)(qu)(qu)約(yue)束支(zhi)(zhi)(zhi)撐(cheng)(cheng)的(de)應用，能夠(gou)全面(mian)進步傳統(tong)的(de)支(zhi)(zhi)(zhi)撐(cheng)(cheng)框架(jia)在中(zhong)震(zhen)(zhen)和大(da)震(zhen)(zhen)下(xia)的(de)抗震(zhen)(zhen)性能。

    屈曲(qu)約束(shu)支撐的要(yao)(yao)由三(san)局部(bu)單(dan)元(yuan)(yuan)(yuan)組成(cheng)：內(nei)部(bu)中(zhong)(zhong)心單(dan)元(yuan)(yuan)(yuan)（芯(xin)材(cai)）、外包(bao)套筒單(dan)元(yuan)(yuan)(yuan)及(ji)滑動約束(shu)單(dan)元(yuan)(yuan)(yuan)，內(nei)部(bu)中(zhong)(zhong)心單(dan)元(yuan)(yuan)(yuan)普通選用低(di)屈從點鋼(gang)材(cai)，常(chang)見的內(nei)核芯(xin)材(cai)截(jie)面方式有一字形(xing)(xing)、十形(xing)(xing)空心矩形(xing)(xing)等，如圖2.2所示，相應的耗能性(xing)能和剛度各不相同(tong)。外包(bao)套管單(dan)元(yuan)(yuan)(yuan)主要(yao)(yao)為(wei)中(zhong)(zhong)心段(duan)提供側向約束(shu)，避免中(zhong)(zhong)心單(dan)元(yuan)(yuan)(yuan)在(zai)滯回受力(li)時發作整體及(ji)部(bu)分失穩。常(chang)見的外圍約束(shu)單(dan)元(yuan)(yuan)(yuan)由圓形(xing)(xing)或方形(xing)(xing)鋼(gang)管中(zhong)(zhong)灌注混凝土或砂漿制成(cheng)。

    常見的(de)(de)滑(hua)動約(yue)束(shu)(shu)單(dan)(dan)(dan)(dan)元(yuan)有(you)無(wu)粘結涂層(ceng)、間隙等(deng)，其作用是(shi)使(shi)得外(wai)包(bao)套管單(dan)(dan)(dan)(dan)元(yuan)僅提供應(ying)中(zhong)(zhong)(zhong)心(xin)(xin)(xin)單(dan)(dan)(dan)(dan)元(yuan)區(qu)段必要(yao)的(de)(de)防(fang)屈曲約(yue)束(shu)(shu)，但(dan)是(shi)不能限(xian)制中(zhong)(zhong)(zhong)心(xin)(xin)(xin)單(dan)(dan)(dan)(dan)元(yuan)橫向(xiang)脹縮變(bian)以(yi)及(ji)縱向(xiang)伸縮變(bian)化。滑(hua)動約(yue)束(shu)(shu)單(dan)(dan)(dan)(dan)元(yuan)以(yi)及(ji)外(wai)包(bao)套管單(dan)(dan)(dan)(dan)元(yuan)共同使(shi)芯材(cai)在(zai)受拉或受壓時(shi)有(you)相同的(de)(de)力(li)學(xue)性能，不至于在(zai)受壓時(shi)由于芯材(cai)中(zhong)(zhong)(zhong)心(xin)(xin)(xin)段單(dan)(dan)(dan)(dan)元(yuan)的(de)(de)收縮遭到外(wai)圍約(yue)束(shu)(shu)而使(shi)支(zhi)撐軸力(li)明(ming)顯變(bian)化。在(zai)中(zhong)(zhong)(zhong)心(xin)(xin)(xin)單(dan)(dan)(dan)(dan)元(yuan)被約(yue)束(shu)(shu)區(qu)域應(ying)涂刷無(wu)粘結涂層(ceng)以(yi)降低接觸摩(mo)擦力(li)。圖2.3中(zhong)(zhong)(zhong)中(zhong)(zhong)(zhong)心(xin)(xin)(xin)單(dan)(dan)(dan)(dan)元(yuan)涂黑局部即為無(wu)粘結涂層(ceng)區(qu)域。

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