It's the same.I think......

武术 is a part of 功夫. besides 武术, 功夫 contains Bruce Lee's Jeet Kun Do and all.

武术 is strict in action while Bruce-like 功夫 make it unlimited and free, and they both are Kung Fu

Using no way as way and having no limitation as limitation. —— Bruce Lee

PS: you can also call 武术 the classical Kung Fu

Or you can call it Chinese Martial Art.

that's a good question.
this summer when olympic games running in china,i saw a talk show about chinese martial art 's applying for one of the olympic games,they invited Jet Lee(李连杰),and he talked about the difference of the kung fu and chinese martial arts. chinese martial arts are a traditional individaual sports,they are extensive and profound,and with a long history,they are so many kinds of ,not only what you saw on TV show or Films.contains knife,spear,staff,bar,fencing,fist position,hand position,foot position etc.And in different area have different styles,some are famous for the staff(as ShaoXin Staff),and some famous for the fist position(Taiji)...i can't give you a general idea of what are chinese martial arts,coz they are so big,if you ask 10 persons,and they give you 10 answers.
Actually,chinese don't say i wanna learn 功夫,they will say i wanna learn shaoxin martial arts,taiji fist or sth else.Chinese martial arts are bigger than kungfu,and somehow,in my opinion,kungfu is kind of shows,and martial art is kind of sports.
so if you wanna learn "中国武术"，choose a style first.

功夫in oral
中国武术in written

中国武术 is an　art，it　is　able　to　make　our　healthy，

功夫　is　a　thing　that　can　guarantee　ur　safety～～