What representations of women, within contemporary theatre, are negative?
Contemporary theatre is defined, typically, as any play written after 1930. Based upon that date, there are many plays which depict women negatively.
Arthur Miller's "The Crucible"- This play depicts Abigail Williams as a deceptive, adulterous, and jealous woman.
Tennessee Williams' "A Streetcar Named Desire"- In this play, Stella is portrayed as a woman who accepts the physical and verbal abuse of her husband, Stanley, solely based upon her undying love for him.
While not considered contemporary when looking at the date written (1879), Ibsen's "A Doll's House" portrays Nora as a lying wife who takes out a loan without her husband's knowledge. The play is still staged today.
That said, many of Shakespeare's plays are still produced today. Many of the women seen in his plays are depicted in negative light. Lady Macbeth (from Macbeth) is a character whose ambition parallels her husbands. She is possesses both murderous plots and is demeaning to her husband (calling his a woman and belittling him repeatedly).